1fetchmail(1) fetchmail reference manual fetchmail(1)
2
6 fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
7
10 fetchmail [option...] [mailserver...]
11 fetchmailconf
12
15 fetchmail is a mail-retrieval and forwarding utility; it fetches mail
16 from remote mailservers and forwards it to your local (client)
17 machine's delivery system. You can then handle the retrieved mail
18 using normal mail user agents such as mutt(1), elm(1) or Mail(1). The
19 fetchmail utility can be run in a daemon mode to repeatedly poll one or
20 more systems at a specified interval.
21 The fetchmail program can gather mail from servers supporting any of
23 the common mail-retrieval protocols: POP2 (legacy, to be removed from
24 future release), POP3, IMAP2bis, IMAP4, and IMAP4rev1. It can also use
25 the ESMTP ETRN extension and ODMR. (The RFCs describing all these pro‐
26 tocols are listed at the end of this manual page.)
27 While fetchmail is primarily intended to be used over on-demand TCP/IP
29 links (such as SLIP or PPP connections), it may also be useful as a
30 message transfer agent for sites which refuse for security reasons to
31 permit (sender-initiated) SMTP transactions with sendmail.
32 SUPPORT, TROUBLESHOOTING
35 For troubleshooting, tracing and debugging, you need to increase fetch‐
36 mail's verbosity to actually see what happens. To do that, please run
37 both of the two following commands, adding all of the options you'd
38 normally use.
39 env LC_ALL=C fetchmail -V -v --nodetach --nosyslog
42 (This command line prints in English how fetchmail understands
44 your configuration.)
45 env LC_ALL=C fetchmail -vvv --nodetach --nosyslog
48 (This command line actually runs fetchmail with verbose English
50 output.)
51 Also see item #G3 in fetchmail's FAQ ⟨http://fetchmail.sourceforge.net/
53 fetchmail-FAQ.html#G3⟩
54 You can omit the LC_ALL=C part above if you want output in the local
56 language (if supported). However if you are posting to mailing lists,
57 please leave it in. The maintainers do not necessarily understand your
58 language, please use English.
59 CONCEPTS
64 If fetchmail is used with a POP or an IMAP server (but not with ETRN or
65 ODMR), it has two fundamental modes of operation for each user account
66 from which it retrieves mail: singledrop- and multidrop-mode.
67 In singledrop-mode,
69 fetchmail assumes that all messages in the user's account (mail‐
70 box) are intended for a single recipient. The identity of the
71 recipient will either default to the local user currently exe‐
72 cuting fetchmail, or will need to be explicitly specified in the
73 configuration file.
74 fetchmail uses singledrop-mode when the fetchmailrc configura‐
76 tion contains at most a single local user specification for a
77 given server account.
78 In multidrop-mode,
80 fetchmail assumes that the mail server account actually contains
81 mail intended for any number of different recipients. There‐
82 fore, fetchmail must attempt to deduce the proper "envelope
83 recipient" from the mail headers of each message. In this mode
84 of operation, fetchmail almost resembles a mail transfer agent
85 (MTA).
86 Note that neither the POP nor IMAP protocols were intended for
88 use in this fashion, and hence envelope information is often not
89 directly available. The ISP must stores the envelope informa‐
90 tion in some message header and. The ISP must also store one
91 copy of the message per recipient. If either of the conditions
92 is not fulfilled, this process is unreliable, because fetchmail
93 must then resort to guessing the true envelope recipient(s) of a
94 message. This usually fails for mailing list messages and Bcc:d
95 mail, or mail for multiple recipients in your domain.
96 fetchmail uses multidrop-mode when more than one local user
98 and/or a wildcard is specified for a particular server account
99 in the configuration file.
100 In ETRN and ODMR modes,
102 these considerations do not apply, as these protocols are based
103 on SMTP, which provides explicit envelope recipient information.
104 These protocols always support multiple recipients.
105 As each message is retrieved, fetchmail normally delivers it via SMTP
107 to port 25 on the machine it is running on (localhost), just as though
108 it were being passed in over a normal TCP/IP link. fetchmail provides
109 the SMTP server with an envelope recipient derived in the manner
110 described previously. The mail will then be delivered according to
111 your MTA's rules (the Mail Transfer Agent is usually sendmail(8),
112 exim(8), or postfix(8)). Invoking your system's MDA (Mail Delivery
113 Agent) is the duty of your MTA. All the delivery-control mechanisms
114 (such as .forward files) normally available through your system MTA and
115 local delivery agents will therefore be applied as usual.
116 If your fetchmail configuration sets a local MDA (see the --mda
118 option), it will be used directly instead of talking SMTP to port 25.
119 If the program fetchmailconf is available, it will assist you in set‐
121 ting up and editing a fetchmailrc configuration. It runs under the X
122 window system and requires that the language Python and the Tk toolkit
123 (with Python bindings) be present on your system. If you are first
124 setting up fetchmail for single-user mode, it is recommended that you
125 use Novice mode. Expert mode provides complete control of fetchmail
126 configuration, including the multidrop features. In either case, the
127 'Autoprobe' button will tell you the most capable protocol a given
128 mailserver supports, and warn you of potential problems with that
129 server.
130
133 The behavior of fetchmail is controlled by command-line options and a
134 run control file, ~/.fetchmailrc, the syntax of which we describe in a
135 later section (this file is what the fetchmailconf program edits).
136 Command-line options override ~/.fetchmailrc declarations.
137 Each server name that you specify following the options on the command
139 line will be queried. If you do not specify any servers on the command
140 line, each 'poll' entry in your ~/.fetchmailrc file will be queried,
141 unless the idle option is used, which see.
142 To facilitate the use of fetchmail in scripts and pipelines, it returns
144 an appropriate exit code upon termination -- see EXIT CODES below.
145 The following options modify the behavior of fetchmail. It is seldom
147 necessary to specify any of these once you have a working .fetchmailrc
148 file set up.
149 Almost all options have a corresponding keyword which can be used to
151 declare them in a .fetchmailrc file.
152 Some special options are not covered here, but are documented instead
154 in sections on AUTHENTICATION and DAEMON MODE which follow.
155 General Options
157 -? | --help
158 Displays option help.
159 -V | --version
161 Displays the version information for your copy of fetchmail. No
162 mail fetch is performed. Instead, for each server specified,
163 all the option information that would be computed if fetchmail
164 were connecting to that server is displayed. Any non-printables
165 in passwords or other string names are shown as backslashed C-
166 like escape sequences. This option is useful for verifying that
167 your options are set the way you want them.
168 -c | --check
170 Return a status code to indicate whether there is mail waiting,
171 without actually fetching or deleting mail (see EXIT CODES
172 below). This option turns off daemon mode (in which it would be
173 useless). It doesn't play well with queries to multiple sites,
174 and doesn't work with ETRN or ODMR. It will return a false pos‐
175 itive if you leave read but undeleted mail in your server mail‐
176 box and your fetch protocol can't tell kept messages from new
177 ones. This means it will work with IMAP, not work with POP2,
178 and may occasionally flake out under POP3.
179 -s | --silent
181 Silent mode. Suppresses all progress/status messages that are
182 normally echoed to standard output during a fetch (but does not
183 suppress actual error messages). The --verbose option overrides
184 this.
185 -v | --verbose
187 Verbose mode. All control messages passed between fetchmail and
188 the mailserver are echoed to stdout. Overrides --silent. Dou‐
189 bling this option (-v -v) causes extra diagnostic information to
190 be printed.
191 --nosoftbounce
193 (since v6.3.10, Keyword: set no softbounce, since v6.3.10)
194 Hard bounce mode. All permanent delivery errors cause messages
195 to be deleted from the upstream server, see "no softbounce"
196 below.
197 --softbounce
199 (since v6.3.10, Keyword: set softbounce, since v6.3.10)
200 Soft bounce mode. All permanent delivery errors cause messages
201 to be left on the upstream server if the protocol supports that.
202 This option is on by default to match historic fetchmail docu‐
203 mentation, and will be changed to hard bounce mode in the next
204 fetchmail release.
205 Disposal Options
207 -a | --all | (since v6.3.3) --fetchall
208 (Keyword: fetchall, since v3.0)
209 Retrieve both old (seen) and new messages from the mailserver.
210 The default is to fetch only messages the server has not marked
211 seen. Under POP3, this option also forces the use of RETR
212 rather than TOP. Note that POP2 retrieval behaves as though
213 --all is always on (see RETRIEVAL FAILURE MODES below) and this
214 option does not work with ETRN or ODMR. While the -a and --all
215 command-line and fetchall rcfile options have been supported for
216 a long time, the --fetchall command-line option was added in
217 v6.3.3.
218 -k | --keep
220 (Keyword: keep)
221 Keep retrieved messages on the remote mailserver. Normally,
222 messages are deleted from the folder on the mailserver after
223 they have been retrieved. Specifying the keep option causes
224 retrieved messages to remain in your folder on the mailserver.
225 This option does not work with ETRN or ODMR. If used with POP3,
226 it is recommended to also specify the --uidl option or uidl key‐
227 word.
228 -K | --nokeep
230 (Keyword: nokeep)
231 Delete retrieved messages from the remote mailserver. This
232 option forces retrieved mail to be deleted. It may be useful if
233 you have specified a default of keep in your .fetchmailrc. This
234 option is forced on with ETRN and ODMR.
235 -F | --flush
237 (Keyword: flush)
238 POP3/IMAP only. This is a dangerous option and can cause mail
239 loss when used improperly. It deletes old (seen) messages from
240 the mailserver before retrieving new messages. Warning: This
241 can cause mail loss if you check your mail with other clients
242 than fetchmail, and cause fetchmail to delete a message it had
243 never fetched before. It can also cause mail loss if the mail
244 server marks the message seen after retrieval (IMAP2 servers).
245 You should probably not use this option in your configuration
246 file. If you use it with POP3, you must use the 'uidl' option.
247 What you probably want is the default setting: if you don't
248 specify '-k', then fetchmail will automatically delete messages
249 after successful delivery.
250 --limitflush
252 POP3/IMAP only, since version 6.3.0. Delete oversized messages
253 from the mailserver before retrieving new messages. The size
254 limit should be separately specified with the --limit option.
255 This option does not work with ETRN or ODMR.
256 Protocol and Query Options
258 -p <proto> | --proto <proto> | --protocol <proto>
259 (Keyword: proto[col])
260 Specify the protocol to use when communicating with the remote
261 mailserver. If no protocol is specified, the default is AUTO.
262 proto may be one of the following:
263 AUTO Tries IMAP, POP3, and POP2 (skipping any of these for
265 which support has not been compiled in).
266 POP2 Post Office Protocol 2 (legacy, to be removed from future
268 release)
269 POP3 Post Office Protocol 3
271 APOP Use POP3 with old-fashioned MD5-challenge authentication.
273 Considered not resistant to man-in-the-middle attacks.
274 RPOP Use POP3 with RPOP authentication.
276 KPOP Use POP3 with Kerberos V4 authentication on port 1109.
278 SDPS Use POP3 with Demon Internet's SDPS extensions.
280 IMAP IMAP2bis, IMAP4, or IMAP4rev1 (fetchmail automatically
282 detects their capabilities).
283 ETRN Use the ESMTP ETRN option.
285 ODMR Use the the On-Demand Mail Relay ESMTP profile.
287 All these alternatives work in basically the same way (communicating
289 with standard server daemons to fetch mail already delivered to a mail‐
290 box on the server) except ETRN and ODMR. The ETRN mode allows you to
291 ask a compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
292 higher) to immediately open a sender-SMTP connection to your client
293 machine and begin forwarding any items addressed to your client machine
294 in the server's queue of undelivered mail. The ODMR mode requires an
295 ODMR-capable server and works similarly to ETRN, except that it does
296 not require the client machine to have a static DNS.
297 -U | --uidl
299 (Keyword: uidl)
300 Force UIDL use (effective only with POP3). Force client-side
301 tracking of 'newness' of messages (UIDL stands for "unique ID
302 listing" and is described in RFC1939). Use with 'keep' to use a
303 mailbox as a baby news drop for a group of users. The fact that
304 seen messages are skipped is logged, unless error logging is
305 done through syslog while running in daemon mode. Note that
306 fetchmail may automatically enable this option depending on
307 upstream server capabilities. Note also that this option may be
308 removed and forced enabled in a future fetchmail version. See
309 also: --idfile.
310 --idle (since 6.3.3)
312 (Keyword: idle, since before 6.0.0)
313 Enable IDLE use (effective only with IMAP). Note that this works
314 with only one account and one folder at a given time, other
315 folders or accounts will not be polled when idle is in effect!
316 While the idle rcfile keyword had been supported for a long
317 time, the --idle command-line option was added in version 6.3.3.
318 IDLE use means that fetchmail tells the IMAP server to send
319 notice of new messages, so they can be retrieved sooner than
320 would be possible with regular polls.
321 -P <portnumber> | --service <servicename>
323 (Keyword: service) Since version 6.3.0.
324 The service option permits you to specify a service name to con‐
325 nect to. You can specify a decimal port number here, if your
326 services database lacks the required service-port assignments.
327 See the FAQ item R12 and the --ssl documentation for details.
328 This replaces the older --port option.
329 --port <portnumber>
331 (Keyword: port)
332 Obsolete version of --service that does not take service names.
333 Note: this option may be removed from a future version.
334 --principal <principal>
336 (Keyword: principal)
337 The principal option permits you to specify a service principal
338 for mutual authentication. This is applicable to POP3 or IMAP
339 with Kerberos 4 authentication only. It does not apply to Ker‐
340 beros 5 or GSSAPI. This option may be removed in a future
341 fetchmail version.
342 -t <seconds> | --timeout <seconds>
344 (Keyword: timeout)
345 The timeout option allows you to set a server-nonresponse time‐
346 out in seconds. If a mailserver does not send a greeting mes‐
347 sage or respond to commands for the given number of seconds,
348 fetchmail will drop the connection to it. Without such a time‐
349 out fetchmail might hang until the TCP connection times out,
350 trying to fetch mail from a down host, which may be very long.
351 This would be particularly annoying for a fetchmail running in
352 the background. There is a default timeout which fetchmail -V
353 will report. If a given connection receives too many timeouts
354 in succession, fetchmail will consider it wedged and stop retry‐
355 ing. The calling user will be notified by email if this hap‐
356 pens.
357 Beginning with fetchmail 6.3.10, the SMTP client uses the recom‐
359 mended minimum timeouts from RFC-5321 while waiting for the
360 SMTP/LMTP server it is talking to. You can raise the timeouts
361 even more, but you cannot shorten them. This is to avoid a
362 painful situation where fetchmail has been configured with a
363 short timeout (a minute or less), ships a long message (many
364 MBytes) to the local MTA, which then takes longer than timeout
365 to respond "OK", which it eventually will; that would mean the
366 mail gets delivered properly, but fetchmail cannot notice it and
367 will thus refetch this big message over and over again.
368 --plugin <command>
370 (Keyword: plugin)
371 The plugin option allows you to use an external program to
372 establish the TCP connection. This is useful if you want to use
373 ssh, or need some special firewalling setup. The program will
374 be looked up in $PATH and can optionally be passed the hostname
375 and port as arguments using "%h" and "%p" respectively (note
376 that the interpolation logic is rather primitive, and these
377 tokens must be bounded by whitespace or beginning of string or
378 end of string). Fetchmail will write to the plugin's stdin and
379 read from the plugin's stdout.
380 --plugout <command>
382 (Keyword: plugout)
383 Identical to the plugin option above, but this one is used for
384 the SMTP connections.
385 -r <name> | --folder <name>
387 (Keyword: folder[s])
388 Causes a specified non-default mail folder on the mailserver (or
389 comma-separated list of folders) to be retrieved. The syntax of
390 the folder name is server-dependent. This option is not avail‐
391 able under POP3, ETRN, or ODMR.
392 --tracepolls
394 (Keyword: tracepolls)
395 Tell fetchmail to poll trace information in the form 'polling
396 account %s' and 'folder %s' to the Received line it generates,
397 where the %s parts are replaced by the user's remote name, the
398 poll label, and the folder (mailbox) where available (the
399 Received header also normally includes the server's true name).
400 This can be used to facilitate mail filtering based on the
401 account it is being received from. The folder information is
402 written only since version 6.3.4.
403 --ssl (Keyword: ssl)
405 Causes the connection to the mail server to be encrypted via
406 SSL, by negotiating SSL directly after connecting (SSL-wrapped
407 mode). Please see the description of --sslproto below! More
408 information is available in the README.SSL file that ships with
409 fetchmail.
410 Note that even if this option is omitted, fetchmail may still
412 negotiate SSL in-band for POP3 or IMAP, through the STLS or
413 STARTTLS feature. You can use the --sslproto option to modify
414 that behavior.
415 If no port is specified, the connection is attempted to the well
417 known port of the SSL version of the base protocol. This is
418 generally a different port than the port used by the base proto‐
419 col. For IMAP, this is port 143 for the clear protocol and port
420 993 for the SSL secured protocol; for POP3, it is port 110 for
421 the clear text and port 995 for the encrypted variant.
422 If your system lacks the corresponding entries from /etc/ser‐
424 vices, see the --service option and specify the numeric port
425 number as given in the previous paragraph (unless your ISP had
426 directed you to different ports, which is uncommon however).
427 --sslcert <name>
429 (Keyword: sslcert)
430 For certificate-based client authentication. Some SSL encrypted
431 servers require client side keys and certificates for authenti‐
432 cation. In most cases, this is optional. This specifies the
433 location of the public key certificate to be presented to the
434 server at the time the SSL session is established. It is not
435 required (but may be provided) if the server does not require
436 it. It may be the same file as the private key (combined key
437 and certificate file) but this is not recommended. Also see
438 --sslkey below.
439 NOTE: If you use client authentication, the user name is fetched
441 from the certificate's CommonName and overrides the name set
442 with --user.
443 --sslkey <name>
445 (Keyword: sslkey)
446 Specifies the file name of the client side private SSL key.
447 Some SSL encrypted servers require client side keys and certifi‐
448 cates for authentication. In most cases, this is optional.
449 This specifies the location of the private key used to sign
450 transactions with the server at the time the SSL session is
451 established. It is not required (but may be provided) if the
452 server does not require it. It may be the same file as the pub‐
453 lic key (combined key and certificate file) but this is not rec‐
454 ommended.
455 If a password is required to unlock the key, it will be prompted
457 for at the time just prior to establishing the session to the
458 server. This can cause some complications in daemon mode.
459 Also see --sslcert above.
461 --sslproto <value>
463 (Keyword: sslproto, NOTE: semantic changes since v6.4.0)
464 This option has a dual use, out of historic fetchmail behaviour.
465 It controls both the SSL/TLS protocol version and, if --ssl is
466 not specified, the STARTTLS behaviour (upgrading the protocol to
467 an SSL or TLS connection in-band). Some other options may how‐
468 ever make TLS mandatory.
469 Only if this option and --ssl are both missing for a poll, there will
471 be opportunistic TLS for POP3 and IMAP, where fetchmail will attempt to
472 upgrade to TLSv1 or newer.
473 Recognized values for --sslproto are given below. You should normally
475 chose one of the auto-negotiating options, i. e. 'auto' or one of the
476 options ending in a plus (+) character. Note that depending on OpenSSL
477 library version and configuration, some options cause run-time errors
478 because the requested SSL or TLS versions are not supported by the par‐
479 ticular installed OpenSSL library.
480 '', the empty string
482 Disable STARTTLS. If --ssl is given for the same server,
483 log an error and pretend that 'auto' had been used
484 instead.
485 'auto' (default). Since v6.4.0. Require TLS. Auto-negotiate
487 TLSv1 or newer, disable SSLv3 downgrade. (fetchmail
488 6.3.26 and older have auto-negotiated all protocols that
489 their OpenSSL library supported, including the broken
490 SSLv3).
491 'SSL23'
493 see 'auto'.
494 'SSL3' Require SSLv3 exactly. SSLv3 is broken, not supported on
496 all systems, avoid it if possible. This will make fetch‐
497 mail negotiate SSLv3 only, and is the only way besides
498 'SSL3+' to have fetchmail 6.4.0 or newer permit SSLv3.
499 'SSL3+'
501 same as 'auto', but permit SSLv3 as well. This is the
502 only way besides 'SSL3' to have fetchmail 6.4.0 or newer
503 permit SSLv3.
504 'TLS1' Require TLSv1. This does not negotiate TLSv1.1 or newer,
506 and is discouraged. Replace by TLS1+ unless the latter
507 chokes your server.
508 'TLS1+'
510 Since v6.4.0. See 'auto'.
511 'TLS1.1'
513 Since v6.4.0. Require TLS v1.1 exactly.
514 'TLS1.1+'
516 Since v6.4.0. Require TLS. Auto-negotiate TLSv1.1 or
517 newer.
518 'TLS1.2'
520 Since v6.4.0. Require TLS v1.2 exactly.
521 'TLS1.2+'
523 Since v6.4.0. Require TLS. Auto-negotiate TLSv1.2 or
524 newer.
525 Unrecognized parameters
527 are treated the same as 'auto'.
528 NOTE: you should hardly ever need to use anything other than ''
530 (to force an unencrypted connection) or 'auto' (to enforce TLS).
531 --sslcertck
533 (Keyword: sslcertck, default enabled since v6.4.0)
534 --sslcertck causes fetchmail to require that SSL/TLS be used and
535 disconnect if it can not successfully negotiate SSL or TLS, or
536 if it cannot successfully verify and validate the certificate
537 and follow it to a trust anchor (or trusted root certificate).
538 The trust anchors are given as a set of local trusted certifi‐
539 cates (see the sslcertfile and sslcertpath options). If the
540 server certificate cannot be obtained or is not signed by one of
541 the trusted ones (directly or indirectly), fetchmail will dis‐
542 connect, regardless of the sslfingerprint option.
543 Note that CRL (certificate revocation lists) are only supported
545 in OpenSSL 0.9.7 and newer! Your system clock should also be
546 reasonably accurate when using this option.
547 Note that this optional behavior may become default behavior in
549 future fetchmail versions.
550 --nosslcertck
552 (Keyword: no sslcertck, only in v6.4.X)
553 The opposite of --sslcertck, this is a disouraged option. It
554 permits fetchmail to continue connecting even if the server cer‐
555 tificate failed the verification checks. Should only be used
556 together with --sslfingerprint.
557 --sslcertfile <file>
559 (Keyword: sslcertfile, since v6.3.17)
560 Sets the file fetchmail uses to look up local certificates. The
561 default is empty. This can be given in addition to --sslcert‐
562 path below, and certificates specified in --sslcertfile will be
563 processed before those in --sslcertpath. The option can be used
564 in addition to --sslcertpath.
565 The file is a text file. It contains the concatenation of
567 trusted CA certificates in PEM format.
568 Note that using this option will suppress loading the default
570 SSL trusted CA certificates file unless you set the environment
571 variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
572 value.
573 --sslcertpath <directory>
575 (Keyword: sslcertpath)
576 Sets the directory fetchmail uses to look up local certificates.
577 The default is your OpenSSL default directory. The directory
578 must be hashed the way OpenSSL expects it - every time you add
579 or modify a certificate in the directory, you need to use the
580 c_rehash tool (which comes with OpenSSL in the tools/ subdirec‐
581 tory). Also, after OpenSSL upgrades, you may need to run
582 c_rehash; particularly when upgrading from 0.9.X to 1.0.0.
583 This can be given in addition to --sslcertfile above, which see
585 for precedence rules.
586 Note that using this option will suppress adding the default SSL
588 trusted CA certificates directory unless you set the environment
589 variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
590 value.
591 --sslcommonname <common name>
593 (Keyword: sslcommonname; since v6.3.9)
594 Use of this option is discouraged. Before using it, contact the
595 administrator of your upstream server and ask for a proper SSL
596 certificate to be used. If that cannot be attained, this option
597 can be used to specify the name (CommonName) that fetchmail
598 expects on the server certificate. A correctly configured
599 server will have this set to the hostname by which it is
600 reached, and by default fetchmail will expect as much. Use this
601 option when the CommonName is set to some other value, to avoid
602 the "Server CommonName mismatch" warning, and only if the
603 upstream server can't be made to use proper certificates.
604 --sslfingerprint <fingerprint>
606 (Keyword: sslfingerprint)
607 Specify the fingerprint of the server key (an MD5 hash of the
608 key) in hexadecimal notation with colons separating groups of
609 two digits. The letter hex digits must be in upper case. This is
610 the format that fetchmail uses to report the fingerprint when an
611 SSL connection is established. When this is specified, fetchmail
612 will compare the server key fingerprint with the given one, and
613 the connection will fail if they do not match, regardless of the
614 sslcertck setting. The connection will also fail if fetchmail
615 cannot obtain an SSL certificate from the server. This can be
616 used to prevent man-in-the-middle attacks, but the finger print
617 from the server must be obtained or verified over a secure chan‐
618 nel, and certainly not over the same Internet connection that
619 fetchmail would use.
620 Using this option will prevent printing certificate verification
622 errors as long as --nosslcertck is in effect.
623 To obtain the fingerprint of a certificate stored in the file
625 cert.pem, try:
626 openssl x509 -in cert.pem -noout -md5 -fingerprint
628 For details, see x509(1ssl).
630 Delivery Control Options
632 -S <hosts> | --smtphost <hosts>
633 (Keyword: smtp[host])
634 Specify a hunt list of hosts to forward mail to (one or more
635 hostnames, comma-separated). Hosts are tried in list order; the
636 first one that is up becomes the forwarding target for the cur‐
637 rent run. If this option is not specified, 'localhost' is used
638 as the default. Each hostname may have a port number following
639 the host name. The port number is separated from the host name
640 by a slash; the default port is "smtp". If you specify an abso‐
641 lute path name (beginning with a /), it will be interpreted as
642 the name of a UNIX socket accepting LMTP connections (such as is
643 supported by the Cyrus IMAP daemon) Example:
644 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
646 This option can be used with ODMR, and will make fetchmail a
648 relay between the ODMR server and SMTP or LMTP receiver.
649 WARNING: if you use address numeric IP addresses here, be sure
651 to use --smtpaddress or --smtpname (either of which see) with a
652 valid SMTP address literal!
653 --fetchdomains <hosts>
655 (Keyword: fetchdomains)
656 In ETRN or ODMR mode, this option specifies the list of domains
657 the server should ship mail for once the connection is turned
658 around. The default is the FQDN of the machine running fetch‐
659 mail.
660 -D <domain> | --smtpaddress <domain>
662 (Keyword: smtpaddress)
663 Specify the domain to be appended to addresses in RCPT TO lines
664 shipped to SMTP. When this is not specified, the name of the
665 SMTP server (as specified by --smtphost) is used for SMTP/LMTP
666 and 'localhost' is used for UNIX socket/BSMTP.
667 NOTE: if you intend to use numeric addresses, or so-called
669 address literals per the SMTP standard, write them in proper
670 SMTP syntax, for instance --smtpaddress "[192.0.2.6]" or --smt‐
671 paddress "[IPv6:2001:DB8::6]".
672 --smtpname <user@domain>
674 (Keyword: smtpname)
675 Specify the domain and user to be put in RCPT TO lines shipped
676 to SMTP. The default user is the current local user. Please
677 also see the NOTE about --smtpaddress and address literals
678 above.
679 -Z <nnn> | --antispam <nnn[, nnn]...>
681 (Keyword: antispam)
682 Specifies the list of numeric SMTP errors that are to be inter‐
683 preted as a spam-block response from the listener. A value of
684 -1 disables this option. For the command-line option, the list
685 values should be comma-separated. Note that the antispam values
686 only apply to "MAIL FROM" responses in the SMTP/LMTP dialogue,
687 but several MTAs (Postfix in its default configuration, qmail)
688 defer the anti-spam response code until after the RCPT TO.
689 --antispam does not work in these circumstances. Also see
690 --softbounce (default) and its inverse.
691 -m <command> | --mda <command>
693 (Keyword: mda)
694 This option lets fetchmail use a Message or Local Delivery Agent
695 (MDA or LDA) directly, rather than forward via SMTP or LMTP.
696 To avoid losing mail, use this option only with MDAs like mail‐
698 drop or MTAs like sendmail that exit with a nonzero status on
699 disk-full and other delivery errors; the nonzero status tells
700 fetchmail that delivery failed and prevents the message from
701 being deleted on the server.
702 If fetchmail is running as root, it sets its user id while
704 delivering mail through an MDA as follows: First, the FETCH‐
705 MAILUSER, LOGNAME, and USER environment variables are checked in
706 this order. The value of the first variable from his list that
707 is defined (even if it is empty!) is looked up in the system
708 user database. If none of the variables is defined, fetchmail
709 will use the real user id it was started with. If one of the
710 variables was defined, but the user stated there isn't found,
711 fetchmail continues running as root, without checking remaining
712 variables on the list. Practically, this means that if you run
713 fetchmail as root (not recommended), it is most useful to define
714 the FETCHMAILUSER environment variable to set the user that the
715 MDA should run as. Some MDAs (such as maildrop) are designed to
716 be setuid root and setuid to the recipient's user id, so you
717 don't lose functionality this way even when running fetchmail as
718 unprivileged user. Check the MDA's manual for details.
719 Some possible MDAs are "/usr/sbin/sendmail -i -f %F -- %T"
721 (Note: some several older or vendor sendmail versions mistake --
722 for an address, rather than an indicator to mark the end of the
723 option arguments), "/usr/bin/deliver" and "/usr/bin/maildrop -d
724 %T". Local delivery addresses will be inserted into the MDA
725 command wherever you place a %T; the mail message's From address
726 will be inserted where you place an %F.
727 Do NOT enclose the %F or %T string in single quotes! For both
729 %T and %F, fetchmail encloses the addresses in single quotes
730 ('), after removing any single quotes they may contain, before
731 the MDA command is passed to the shell.
732 Do NOT use an MDA invocation that dispatches on the contents of
734 To/Cc/Bcc, like "sendmail -i -t" or "qmail-inject", it will cre‐
735 ate mail loops and bring the just wrath of many postmasters down
736 upon your head. This is one of the most frequent configuration
737 errors!
738 Also, do not try to combine multidrop mode with an MDA such as
740 maildrop that can only accept one address, unless your upstream
741 stores one copy of the message per recipient and transports the
742 envelope recipient in a header; you will lose mail.
743 The well-known procmail(1) package is very hard to configure
745 properly, it has a very nasty "fall through to the next rule"
746 behavior on delivery errors (even temporary ones, such as out of
747 disk space if another user's mail daemon copies the mailbox
748 around to purge old messages), so your mail will end up in the
749 wrong mailbox sooner or later. The proper procmail configuration
750 is outside the scope of this document. Using maildrop(1) is usu‐
751 ally much easier, and many users find the filter syntax used by
752 maildrop easier to understand.
753 Finally, we strongly advise that you do not use qmail-inject.
755 The command line interface is non-standard without providing
756 benefits for typical use, and fetchmail makes no attempts to
757 accommodate qmail-inject's deviations from the standard. Some of
758 qmail-inject's command-line and environment options are actually
759 dangerous and can cause broken threads, non-detected duplicate
760 messages and forwarding loops.
761 --lmtp (Keyword: lmtp)
764 Cause delivery via LMTP (Local Mail Transfer Protocol). A ser‐
765 vice host and port must be explicitly specified on each host in
766 the smtphost hunt list (see above) if this option is selected;
767 the default port 25 will (in accordance with RFC 2033) not be
768 accepted.
769 --bsmtp <filename>
771 (Keyword: bsmtp)
772 Append fetched mail to a BSMTP file. This simply contains the
773 SMTP commands that would normally be generated by fetchmail when
774 passing mail to an SMTP listener daemon.
775 An argument of '-' causes the SMTP batch to be written to stan‐
777 dard output, which is of limited use: this only makes sense for
778 debugging, because fetchmail's regular output is interspersed on
779 the same channel, so this isn't suitable for mail delivery. This
780 special mode may be removed in a later release.
781 Note that fetchmail's reconstruction of MAIL FROM and RCPT TO
783 lines is not guaranteed correct; the caveats discussed under THE
784 USE AND ABUSE OF MULTIDROP MAILBOXES below apply. This mode has
785 precedence before --mda and SMTP/LMTP.
786 --bad-header {reject|accept}
788 (Keyword: bad-header; since v6.3.15)
789 Specify how fetchmail is supposed to treat messages with bad
790 headers, i. e. headers with bad syntax. Traditionally, fetchmail
791 has rejected such messages, but some distributors modified
792 fetchmail to accept them. You can now configure fetchmail's be‐
793 haviour per server.
794 Resource Limit Control Options
797 -l <maxbytes> | --limit <maxbytes>
798 (Keyword: limit)
799 Takes a maximum octet size argument, where 0 is the default and
800 also the special value designating "no limit". If nonzero, mes‐
801 sages larger than this size will not be fetched and will be left
802 on the server (in foreground sessions, the progress messages
803 will note that they are "oversized"). If the fetch protocol
804 permits (in particular, under IMAP or POP3 without the fetchall
805 option) the message will not be marked seen.
806 An explicit --limit of 0 overrides any limits set in your run
808 control file. This option is intended for those needing to
809 strictly control fetch time due to expensive and variable phone
810 rates.
811 Combined with --limitflush, it can be used to delete oversized
813 messages waiting on a server. In daemon mode, oversize notifi‐
814 cations are mailed to the calling user (see the --warnings
815 option). This option does not work with ETRN or ODMR.
816 -w <interval> | --warnings <interval>
818 (Keyword: warnings)
819 Takes an interval in seconds. When you call fetchmail with a
820 'limit' option in daemon mode, this controls the interval at
821 which warnings about oversized messages are mailed to the call‐
822 ing user (or the user specified by the 'postmaster' option).
823 One such notification is always mailed at the end of the the
824 first poll that the oversized message is detected. Thereafter,
825 re-notification is suppressed until after the warning interval
826 elapses (it will take place at the end of the first following
827 poll).
828 -b <count> | --batchlimit <count>
830 (Keyword: batchlimit)
831 Specify the maximum number of messages that will be shipped to
832 an SMTP listener before the connection is deliberately torn down
833 and rebuilt (defaults to 0, meaning no limit). An explicit
834 --batchlimit of 0 overrides any limits set in your run control
835 file. While sendmail(8) normally initiates delivery of a mes‐
836 sage immediately after receiving the message terminator, some
837 SMTP listeners are not so prompt. MTAs like smail(8) may wait
838 till the delivery socket is shut down to deliver. This may pro‐
839 duce annoying delays when fetchmail is processing very large
840 batches. Setting the batch limit to some nonzero size will pre‐
841 vent these delays. This option does not work with ETRN or ODMR.
842 -B <number> | --fetchlimit <number>
844 (Keyword: fetchlimit)
845 Limit the number of messages accepted from a given server in a
846 single poll. By default there is no limit. An explicit --fetch‐
847 limit of 0 overrides any limits set in your run control file.
848 This option does not work with ETRN or ODMR.
849 --fetchsizelimit <number>
851 (Keyword: fetchsizelimit)
852 Limit the number of sizes of messages accepted from a given
853 server in a single transaction. This option is useful in reduc‐
854 ing the delay in downloading the first mail when there are too
855 many mails in the mailbox. By default, the limit is 100. If
856 set to 0, sizes of all messages are downloaded at the start.
857 This option does not work with ETRN or ODMR. For POP3, the only
858 valid non-zero value is 1.
859 --fastuidl <number>
861 (Keyword: fastuidl)
862 Do a binary instead of linear search for the first unseen UID.
863 Binary search avoids downloading the UIDs of all mails. This
864 saves time (especially in daemon mode) where downloading the
865 same set of UIDs in each poll is a waste of bandwidth. The num‐
866 ber 'n' indicates how rarely a linear search should be done. In
867 daemon mode, linear search is used once followed by binary
868 searches in 'n-1' polls if 'n' is greater than 1; binary search
869 is always used if 'n' is 1; linear search is always used if 'n'
870 is 0. In non-daemon mode, binary search is used if 'n' is 1;
871 otherwise linear search is used. The default value of 'n' is 4.
872 This option works with POP3 only.
873 -e <count> | --expunge <count>
875 (Keyword: expunge)
876 Arrange for deletions to be made final after a given number of
877 messages. Under POP2 or POP3, fetchmail cannot make deletions
878 final without sending QUIT and ending the session -- with this
879 option on, fetchmail will break a long mail retrieval session
880 into multiple sub-sessions, sending QUIT after each sub-session.
881 This is a good defense against line drops on POP3 servers.
882 Under IMAP, fetchmail normally issues an EXPUNGE command after
883 each deletion in order to force the deletion to be done immedi‐
884 ately. This is safest when your connection to the server is
885 flaky and expensive, as it avoids resending duplicate mail after
886 a line hit. However, on large mailboxes the overhead of re-
887 indexing after every message can slam the server pretty hard, so
888 if your connection is reliable it is good to do expunges less
889 frequently. Also note that some servers enforce a delay of a
890 few seconds after each quit, so fetchmail may not be able to get
891 back in immediately after an expunge -- you may see "lock busy"
892 errors if this happens. If you specify this option to an integer
893 N, it tells fetchmail to only issue expunges on every Nth
894 delete. An argument of zero suppresses expunges entirely (so no
895 expunges at all will be done until the end of run). This option
896 does not work with ETRN or ODMR.
897 Authentication Options
900 -u <name> | --user <name> | --username <name>
901 (Keyword: user[name])
902 Specifies the user identification to be used when logging in to
903 the mailserver. The appropriate user identification is both
904 server and user-dependent. The default is your login name on
905 the client machine that is running fetchmail. See USER AUTHEN‐
906 TICATION below for a complete description.
907 -I <specification> | --interface <specification>
909 (Keyword: interface)
910 Require that a specific interface device be up and have a spe‐
911 cific local or remote IPv4 (IPv6 is not supported by this option
912 yet) address (or range) before polling. Frequently fetchmail is
913 used over a transient point-to-point TCP/IP link established
914 directly to a mailserver via SLIP or PPP. That is a relatively
915 secure channel. But when other TCP/IP routes to the mailserver
916 exist (e.g. when the link is connected to an alternate ISP),
917 your username and password may be vulnerable to snooping (espe‐
918 cially when daemon mode automatically polls for mail, shipping a
919 clear password over the net at predictable intervals). The
920 --interface option may be used to prevent this. When the speci‐
921 fied link is not up or is not connected to a matching IP
922 address, polling will be skipped. The format is:
923 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
925 The field before the first slash is the interface name (i.e.
927 sl0, ppp0 etc.). The field before the second slash is the
928 acceptable IP address. The field after the second slash is a
929 mask which specifies a range of IP addresses to accept. If no
930 mask is present 255.255.255.255 is assumed (i.e. an exact
931 match). This option is currently only supported under Linux and
932 FreeBSD. Please see the monitor section for below for FreeBSD
933 specific information.
934 Note that this option may be removed from a future fetchmail
936 version.
937 -M <interface> | --monitor <interface>
939 (Keyword: monitor)
940 Daemon mode can cause transient links which are automatically
941 taken down after a period of inactivity (e.g. PPP links) to
942 remain up indefinitely. This option identifies a system TCP/IP
943 interface to be monitored for activity. After each poll inter‐
944 val, if the link is up but no other activity has occurred on the
945 link, then the poll will be skipped. However, when fetchmail is
946 woken up by a signal, the monitor check is skipped and the poll
947 goes through unconditionally. This option is currently only
948 supported under Linux and FreeBSD. For the monitor and inter‐
949 face options to work for non root users under FreeBSD, the
950 fetchmail binary must be installed SGID kmem. This would be a
951 security hole, but fetchmail runs with the effective GID set to
952 that of the kmem group only when interface data is being col‐
953 lected.
954 Note that this option may be removed from a future fetchmail
956 version.
957 --auth <type>
959 (Keyword: auth[enticate])
960 This option permits you to specify an authentication type (see
961 USER AUTHENTICATION below for details). The possible values are
962 any, password, kerberos_v5, kerberos (or, for excruciating
963 exactness, kerberos_v4), gssapi, cram-md5, otp, ntlm, msn (only
964 for POP3), external (only IMAP) and ssh. When any (the default)
965 is specified, fetchmail tries first methods that don't require a
966 password (EXTERNAL, GSSAPI, KERBEROS IV, KERBEROS 5); then it
967 looks for methods that mask your password (CRAM-MD5, NTLM, X-OTP
968 - note that MSN is only supported for POP3, but not autoprobed);
969 and only if the server doesn't support any of those will it ship
970 your password en clair. Other values may be used to force vari‐
971 ous authentication methods (ssh suppresses authentication and is
972 thus useful for IMAP PREAUTH). (external suppresses authentica‐
973 tion and is thus useful for IMAP EXTERNAL). Any value other
974 than password, cram-md5, ntlm, msn or otp suppresses fetchmail's
975 normal inquiry for a password. Specify ssh when you are using
976 an end-to-end secure connection such as an ssh tunnel; specify
977 external when you use TLS with client authentication and specify
978 gssapi or kerberos_v4 if you are using a protocol variant that
979 employs GSSAPI or K4. Choosing KPOP protocol automatically
980 selects Kerberos authentication. This option does not work with
981 ETRN. GSSAPI service names are in line with RFC-2743 and IANA
982 registrations, see Generic Security Service Application Program
983 Interface (GSSAPI)/Kerberos/Simple Authentication and Security
984 Layer (SASL) Service Names ⟨http://www.iana.org/assignments/
985 gssapi-service-names/⟩.
986 Miscellaneous Options
988 -f <pathname> | --fetchmailrc <pathname>
989 Specify a non-default name for the ~/.fetchmailrc run control
990 file. The pathname argument must be either "-" (a single dash,
991 meaning to read the configuration from standard input) or a
992 filename. Unless the --version option is also on, a named file
993 argument must have permissions no more open than 0700
994 (u=rwx,g=,o=) or else be /dev/null.
995 -i <pathname> | --idfile <pathname>
997 (Keyword: idfile)
998 Specify an alternate name for the .fetchids file used to save
999 message UIDs. NOTE: since fetchmail 6.3.0, write access to the
1000 directory containing the idfile is required, as fetchmail writes
1001 a temporary file and renames it into the place of the real
1002 idfile only if the temporary file has been written successfully.
1003 This avoids the truncation of idfiles when running out of disk
1004 space.
1005 --pidfile <pathname>
1007 (Keyword: pidfile; since fetchmail v6.3.4)
1008 Override the default location of the PID file. Default: see
1009 "ENVIRONMENT" below.
1010 -n | --norewrite
1012 (Keyword: no rewrite)
1013 Normally, fetchmail edits RFC-822 address headers (To, From, Cc,
1014 Bcc, and Reply-To) in fetched mail so that any mail IDs local to
1015 the server are expanded to full addresses (@ and the mailserver
1016 hostname are appended). This enables replies on the client to
1017 get addressed correctly (otherwise your mailer might think they
1018 should be addressed to local users on the client machine!).
1019 This option disables the rewrite. (This option is provided to
1020 pacify people who are paranoid about having an MTA edit mail
1021 headers and want to know they can prevent it, but it is gener‐
1022 ally not a good idea to actually turn off rewrite.) When using
1023 ETRN or ODMR, the rewrite option is ineffective.
1024 -E <line> | --envelope <line>
1026 (Keyword: envelope; Multidrop only)
1027 In the configuration file, an enhanced syntax is used:
1028 envelope [<count>] <line>
1029 This option changes the header fetchmail assumes will carry a
1031 copy of the mail's envelope address. Normally this is 'X-Enve‐
1032 lope-To'. Other typically found headers to carry envelope
1033 information are 'X-Original-To' and 'Delivered-To'. Now, since
1034 these headers are not standardized, practice varies. See the
1035 discussion of multidrop address handling below. As a special
1036 case, 'envelope "Received"' enables parsing of sendmail-style
1037 Received lines. This is the default, but discouraged because it
1038 is not fully reliable.
1039 Note that fetchmail expects the Received-line to be in a spe‐
1041 cific format: It must contain "by host for address", where host
1042 must match one of the mailserver names that fetchmail recognizes
1043 for the account in question.
1044 The optional count argument (only available in the configuration
1046 file) determines how many header lines of this kind are skipped.
1047 A count of 1 means: skip the first, take the second. A count of
1048 2 means: skip the first and second, take the third, and so on.
1049 -Q <prefix> | --qvirtual <prefix>
1051 (Keyword: qvirtual; Multidrop only)
1052 The string prefix assigned to this option will be removed from
1053 the user name found in the header specified with the envelope
1054 option (before doing multidrop name mapping or localdomain
1055 checking, if either is applicable). This option is useful if you
1056 are using fetchmail to collect the mail for an entire domain and
1057 your ISP (or your mail redirection provider) is using qmail.
1058 One of the basic features of qmail is the Delivered-To: message
1059 header. Whenever qmail delivers a message to a local mailbox it
1060 puts the username and hostname of the envelope recipient on this
1061 line. The major reason for this is to prevent mail loops. To
1062 set up qmail to batch mail for a disconnected site the ISP-mail‐
1063 host will have normally put that site in its 'Virtualhosts' con‐
1064 trol file so it will add a prefix to all mail addresses for this
1065 site. This results in mail sent to 'username@userhost.user‐
1066 dom.dom.com' having a Delivered-To: line of the form:
1067 Delivered-To: mbox-userstr-username@userhost.example.com
1069 The ISP can make the 'mbox-userstr-' prefix anything they choose
1071 but a string matching the user host name is likely. By using
1072 the option 'envelope Delivered-To:' you can make fetchmail reli‐
1073 ably identify the original envelope recipient, but you have to
1074 strip the 'mbox-userstr-' prefix to deliver to the correct user.
1075 This is what this option is for.
1076 --configdump
1078 Parse the ~/.fetchmailrc file, interpret any command-line
1079 options specified, and dump a configuration report to standard
1080 output. The configuration report is a data structure assignment
1081 in the language Python. This option is meant to be used with an
1082 interactive ~/.fetchmailrc editor like fetchmailconf, written in
1083 Python.
1084 -y | --yydebug
1086 Enables parser debugging, this option is meant to be used by
1087 developers only.
1088 Removed Options
1091 -T | --netsec
1092 Removed before version 6.3.0, the required underlying inet6_apps
1093 library had been discontinued and is no longer available.
1094
1097 All modes except ETRN require authentication of the client to the
1098 server. Normal user authentication in fetchmail is very much like the
1099 authentication mechanism of ftp(1). The correct user-id and password
1100 depend upon the underlying security system at the mailserver.
1101 If the mailserver is a Unix machine on which you have an ordinary user
1103 account, your regular login name and password are used with fetchmail.
1104 If you use the same login name on both the server and the client
1105 machines, you needn't worry about specifying a user-id with the -u
1106 option -- the default behavior is to use your login name on the client
1107 machine as the user-id on the server machine. If you use a different
1108 login name on the server machine, specify that login name with the -u
1109 option. e.g. if your login name is 'jsmith' on a machine named 'mail‐
1110 grunt', you would start fetchmail as follows:
1111 fetchmail -u jsmith mailgrunt
1113 The default behavior of fetchmail is to prompt you for your mailserver
1115 password before the connection is established. This is the safest way
1116 to use fetchmail and ensures that your password will not be compro‐
1117 mised. You may also specify your password in your ~/.fetchmailrc file.
1118 This is convenient when using fetchmail in daemon mode or with scripts.
1119 Using netrc files
1122 If you do not specify a password, and fetchmail cannot extract one from
1123 your ~/.fetchmailrc file, it will look for a ~/.netrc file in your home
1124 directory before requesting one interactively; if an entry matching the
1125 mailserver is found in that file, the password will be used. Fetchmail
1126 first looks for a match on poll name; if it finds none, it checks for a
1127 match on via name. See the ftp(1) man page for details of the syntax
1128 of the ~/.netrc file. To show a practical example, a .netrc might look
1129 like this:
1130 machine hermes.example.org
1132 login joe
1133 password topsecret
1134 You can repeat this block with different user information if you need
1136 to provide more than one password.
1137 This feature may allow you to avoid duplicating password information in
1139 more than one file.
1140 On mailservers that do not provide ordinary user accounts, your user-id
1142 and password are usually assigned by the server administrator when you
1143 apply for a mailbox on the server. Contact your server administrator
1144 if you don't know the correct user-id and password for your mailbox
1145 account.
1146
1148 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
1149 independent authentication using the .rhosts file on the mailserver
1150 side. Under this RPOP variant, a fixed per-user ID equivalent to a
1151 password was sent in clear over a link to a reserved port, with the
1152 command RPOP rather than PASS to alert the server that it should do
1153 special checking. RPOP is supported by fetchmail (you can specify
1154 'protocol RPOP' to have the program send 'RPOP' rather than 'PASS') but
1155 its use is strongly discouraged, and support will be removed from a
1156 future fetchmail version. This facility was vulnerable to spoofing and
1157 was withdrawn in RFC1460.
1158 RFC1460 introduced APOP authentication. In this variant of POP3, you
1160 register an APOP password on your server host (on some servers, the
1161 program to do this is called popauth(8)). You put the same password in
1162 your ~/.fetchmailrc file. Each time fetchmail logs in, it sends an MD5
1163 hash of your password and the server greeting time to the server, which
1164 can verify it by checking its authorization database.
1165 Note that APOP is no longer considered resistant against man-in-the-
1167 middle attacks.
1168 RETR or TOP
1170 fetchmail makes some efforts to make the server believe messages had
1171 not been retrieved, by using the TOP command with a large number of
1172 lines when possible. TOP is a command that retrieves the full header
1173 and a fetchmail-specified amount of body lines. It is optional and
1174 therefore not implemented by all servers, and some are known to imple‐
1175 ment it improperly. On many servers however, the RETR command which
1176 retrieves the full message with header and body, sets the "seen" flag
1177 (for instance, in a web interface), whereas the TOP command does not do
1178 that.
1179 fetchmail will always use the RETR command if "fetchall" is set.
1181 fetchmail will also use the RETR command if "keep" is set and "uidl" is
1182 unset. Finally, fetchmail will use the RETR command on Maillennium
1183 POP3/PROXY servers (used by Comcast) to avoid a deliberate TOP misin‐
1184 terpretation in this server that causes message corruption.
1185 In all other cases, fetchmail will use the TOP command. This implies
1187 that in "keep" setups, "uidl" must be set if "TOP" is desired.
1188 Note that this description is true for the current version of fetch‐
1190 mail, but the behavior may change in future versions. In particular,
1191 fetchmail may prefer the RETR command because the TOP command causes
1192 much grief on some servers and is only optional.
1193
1195 If your fetchmail was built with Kerberos support and you specify Ker‐
1196 beros authentication (either with --auth or the .fetchmailrc option
1197 authenticate kerberos_v4) it will try to get a Kerberos ticket from the
1198 mailserver at the start of each query. Note: if either the pollname or
1199 via name is 'hesiod', fetchmail will try to use Hesiod to look up the
1200 mailserver.
1201 If you use POP3 or IMAP with GSSAPI authentication, fetchmail will
1203 expect the server to have RFC1731- or RFC1734-conforming GSSAPI capa‐
1204 bility, and will use it. Currently this has only been tested over Ker‐
1205 beros V, so you're expected to already have a ticket-granting ticket.
1206 You may pass a username different from your principal name using the
1207 standard --user command or by the .fetchmailrc option user.
1208 If your IMAP daemon returns the PREAUTH response in its greeting line,
1210 fetchmail will notice this and skip the normal authentication step.
1211 This can be useful, e.g. if you start imapd explicitly using ssh. In
1212 this case you can declare the authentication value 'ssh' on that site
1213 entry to stop .fetchmail from asking you for a password when it starts
1214 up.
1215 If you use client authentication with TLS1 and your IMAP daemon returns
1217 the AUTH=EXTERNAL response, fetchmail will notice this and will use the
1218 authentication shortcut and will not send the passphrase. In this case
1219 you can declare the authentication value 'external'
1220 on that site to stop fetchmail from asking you for a password when it
1221 starts up.
1222 If you are using POP3, and the server issues a one-time-password chal‐
1224 lenge conforming to RFC1938, fetchmail will use your password as a pass
1225 phrase to generate the required response. This avoids sending secrets
1226 over the net unencrypted.
1227 Compuserve's RPA authentication is supported. If you compile in the
1229 support, fetchmail will try to perform an RPA pass-phrase authentica‐
1230 tion instead of sending over the password en clair if it detects "@com‐
1231 puserve.com" in the hostname.
1232 If you are using IMAP, Microsoft's NTLM authentication (used by Micro‐
1234 soft Exchange) is supported. If you compile in the support, fetchmail
1235 will try to perform an NTLM authentication (instead of sending over the
1236 password en clair) whenever the server returns AUTH=NTLM in its capa‐
1237 bility response. Specify a user option value that looks like
1238 'user@domain': the part to the left of the @ will be passed as the
1239 username and the part to the right as the NTLM domain.
1240 Secure Socket Layers (SSL) and Transport Layer Security (TLS)
1243 transport. Additionally, POP3 and IMAP retrival can also negotiate
1244 SSL/TLS by means of STARTTLS (or STLS).
1245 Note that fetchmail currently uses the OpenSSL library, which is se‐
1247 verely underdocumented, so failures may occur just because the program‐
1248 mers are not aware of OpenSSL's requirement of the day. For instance,
1249 since v6.3.16, fetchmail calls OpenSSL_add_all_algorithms(), which is
1250 necessary to support certificates using SHA256 on OpenSSL 0.9.8 -- this
1251 information is deeply hidden in the documentation and not at all obvi‐
1252 ous. Please do not hesitate to report subtle SSL failures.
1253 You can access SSL encrypted services by specifying the options start‐
1255 ing with --ssl, such as --ssl, --sslproto, --sslcertck, and others.
1256 You can also do this using the corresponding user options in the
1257 .fetchmailrc file. Some services, such as POP3 and IMAP, have differ‐
1258 ent well known ports defined for the SSL encrypted services. The
1259 encrypted ports will be selected automatically when SSL is enabled and
1260 no explicit port is specified. Also, the --sslcertck command line or
1261 sslcertck run control file option should be used to force strict cer‐
1262 tificate checking with older fetchmail versions - see below.
1263 If SSL is not configured, fetchmail will usually opportunistically try
1265 to use STARTTLS. STARTTLS can be enforced by using --sslproto auto and
1266 defeated by using --sslproto ''. TLS connections use the same port as
1267 the unencrypted version of the protocol and negotiate TLS via special
1268 command. The --sslcertck command line or sslcertck run control file
1269 option should be used to force strict certificate checking - see below.
1270 --sslcertck is recommended: When connecting to an SSL or TLS encrypted
1272 server, the server presents a certificate to the client for validation.
1273 The certificate is checked to verify that the common name in the cer‐
1274 tificate matches the name of the server being contacted and that the
1275 effective and expiration dates in the certificate indicate that it is
1276 currently valid. If any of these checks fail, a warning message is
1277 printed, but the connection continues. The server certificate does not
1278 need to be signed by any specific Certifying Authority and may be a
1279 "self-signed" certificate. If the --sslcertck command line option or
1280 sslcertck run control file option is used, fetchmail will instead abort
1281 if any of these checks fail, because it must assume that there is a
1282 man-in-the-middle attack in this scenario, hence fetchmail must not
1283 expose cleartext passwords. Use of the sslcertck or --sslcertck option
1284 is therefore advised; it has become the default in fetchmail 6.4.0.
1285 Some SSL encrypted servers may request a client side certificate. A
1287 client side public SSL certificate and private SSL key may be speci‐
1288 fied. If requested by the server, the client certificate is sent to
1289 the server for validation. Some servers may require a valid client
1290 certificate and may refuse connections if a certificate is not provided
1291 or if the certificate is not valid. Some servers may require client
1292 side certificates be signed by a recognized Certifying Authority. The
1293 format for the key files and the certificate files is that required by
1294 the underlying SSL libraries (OpenSSL in the general case).
1295 A word of care about the use of SSL: While above mentioned setup with
1297 self-signed server certificates retrieved over the wires can protect
1298 you from a passive eavesdropper, it doesn't help against an active
1299 attacker. It's clearly an improvement over sending the passwords in
1300 clear, but you should be aware that a man-in-the-middle attack is triv‐
1301 ially possible (in particular with tools such as dsniff ⟨http://
1302 monkey.org/~dugsong/dsniff/⟩, ). Use of strict certificate checking
1303 with a certification authority recognized by server and client, or per‐
1304 haps of an SSH tunnel (see below for some examples) is preferable if
1305 you care seriously about the security of your mailbox and passwords.
1306 ESMTP AUTH
1309 fetchmail also supports authentication to the ESMTP server on the
1310 client side according to RFC 2554. You can specify a name/password
1311 pair to be used with the keywords 'esmtpname' and 'esmtppassword'; the
1312 former defaults to the username of the calling user.
1313
1316 Introducing the daemon mode
1317 In daemon mode, fetchmail puts itself into the background and runs for‐
1318 ever, querying each specified host and then sleeping for a given
1319 polling interval.
1320 Starting the daemon mode
1322 There are several ways to make fetchmail work in daemon mode. On the
1323 command line, --daemon <interval> or -d <interval> option runs fetch‐
1324 mail in daemon mode. You must specify a numeric argument which is a
1325 polling interval (time to wait after completing a whole poll cycle with
1326 the last server and before starting the next poll cycle with the first
1327 server) in seconds.
1328 Example: simply invoking
1330 fetchmail -d 900
1332 will, therefore, poll all the hosts described in your ~/.fetchmailrc
1334 file (except those explicitly excluded with the 'skip' verb) a bit less
1335 often than once every 15 minutes (exactly: 15 minutes + time that the
1336 poll takes).
1337 It is also possible to set a polling interval in your ~/.fetchmailrc
1339 file by saying 'set daemon <interval>', where <interval> is an integer
1340 number of seconds. If you do this, fetchmail will always start in dae‐
1341 mon mode unless you override it with the command-line option --daemon 0
1342 or -d0.
1343 Only one daemon process is permitted per user; in daemon mode, fetch‐
1345 mail sets up a per-user lockfile to guarantee this. (You can however
1346 cheat and set the FETCHMAILHOME environment variable to overcome this
1347 setting, but in that case, it is your responsibility to make sure you
1348 aren't polling the same server with two processes at the same time.)
1349 Awakening the background daemon
1351 Normally, calling fetchmail with a daemon in the background sends a
1352 wake-up signal to the daemon and quits without output. The background
1353 daemon then starts its next poll cycle immediately. The wake-up sig‐
1354 nal, SIGUSR1, can also be sent manually. The wake-up action also clears
1355 any 'wedged' flags indicating that connections have wedged due to
1356 failed authentication or multiple timeouts.
1357 Terminating the background daemon
1359 The option -q or --quit will kill a running daemon process instead of
1360 waking it up (if there is no such process, fetchmail will notify you).
1361 If the --quit option appears last on the command line, fetchmail will
1362 kill the running daemon process and then quit. Otherwise, fetchmail
1363 will first kill a running daemon process and then continue running with
1364 the other options.
1365 Useful options for daemon mode
1367 The -L <filename> or --logfile <filename> option (keyword: set logfile)
1368 is only effective when fetchmail is detached and in daemon mode. Note
1369 that the logfile must exist before fetchmail is run, you can use the
1370 touch(1) command with the filename as its sole argument to create it.
1371 This option allows you to redirect status messages into a specified
1372 logfile (follow the option with the logfile name). The logfile is
1373 opened for append, so previous messages aren't deleted. This is pri‐
1374 marily useful for debugging configurations. Note that fetchmail does
1375 not detect if the logfile is rotated, the logfile is only opened once
1376 when fetchmail starts. You need to restart fetchmail after rotating the
1377 logfile and before compressing it (if applicable).
1378 The --syslog option (keyword: set syslog) allows you to redirect status
1380 and error messages emitted to the syslog(3) system daemon if available.
1381 Messages are logged with an id of fetchmail, the facility LOG_MAIL, and
1382 priorities LOG_ERR, LOG_ALERT or LOG_INFO. This option is intended for
1383 logging status and error messages which indicate the status of the dae‐
1384 mon and the results while fetching mail from the server(s). Error mes‐
1385 sages for command line options and parsing the .fetchmailrc file are
1386 still written to stderr, or to the specified log file. The --nosyslog
1387 option turns off use of syslog(3), assuming it's turned on in the
1388 ~/.fetchmailrc file. This option is overridden, in certain situations,
1389 by --logfile (which see).
1390 The -N or --nodetach option suppresses backgrounding and detachment of
1392 the daemon process from its control terminal. This is useful for
1393 debugging or when fetchmail runs as the child of a supervisor process
1394 such as init(8) or Gerrit Pape's runit(8). Note that this also causes
1395 the logfile option to be ignored.
1396 Note that while running in daemon mode polling a POP2 or IMAP2bis
1398 server, transient errors (such as DNS failures or sendmail delivery
1399 refusals) may force the fetchall option on for the duration of the next
1400 polling cycle. This is a robustness feature. It means that if a mes‐
1401 sage is fetched (and thus marked seen by the mailserver) but not deliv‐
1402 ered locally due to some transient error, it will be re-fetched during
1403 the next poll cycle. (The IMAP logic doesn't delete messages until
1404 they're delivered, so this problem does not arise.)
1405 If you touch or change the ~/.fetchmailrc file while fetchmail is run‐
1407 ning in daemon mode, this will be detected at the beginning of the next
1408 poll cycle. When a changed ~/.fetchmailrc is detected, fetchmail
1409 rereads it and restarts from scratch (using exec(2); no state informa‐
1410 tion is retained in the new instance). Note that if fetchmail needs to
1411 query for passwords, of that if you break the ~/.fetchmailrc file's
1412 syntax, the new instance will softly and silently vanish away on
1413 startup.
1414
1417 The --postmaster <name> option (keyword: set postmaster) specifies the
1418 last-resort username to which multidrop mail is to be forwarded if no
1419 matching local recipient can be found. It is also used as destination
1420 of undeliverable mail if the 'bouncemail' global option is off and
1421 additionally for spam-blocked mail if the 'bouncemail' global option is
1422 off and the 'spambounce' global option is on. This option defaults to
1423 the user who invoked fetchmail. If the invoking user is root, then the
1424 default of this option is the user 'postmaster'. Setting postmaster to
1425 the empty string causes such mail as described above to be discarded -
1426 this however is usually a bad idea. See also the description of the
1427 'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.
1428 The --nobounce behaves like the "set no bouncemail" global option,
1430 which see.
1431 The --invisible option (keyword: set invisible) tries to make fetchmail
1433 invisible. Normally, fetchmail behaves like any other MTA would -- it
1434 generates a Received header into each message describing its place in
1435 the chain of transmission, and tells the MTA it forwards to that the
1436 mail came from the machine fetchmail itself is running on. If the
1437 invisible option is on, the Received header is suppressed and fetchmail
1438 tries to spoof the MTA it forwards to into thinking it came directly
1439 from the mailserver host.
1440 The --showdots option (keyword: set showdots) forces fetchmail to show
1442 progress dots even if the output goes to a file or fetchmail is not in
1443 verbose mode. Fetchmail shows the dots by default when run in --ver‐
1444 bose mode and output goes to console. This option is ignored in
1445 --silent mode.
1446 By specifying the --tracepolls option, you can ask fetchmail to add
1448 information to the Received header on the form "polling {label} account
1449 {user}", where {label} is the account label (from the specified rcfile,
1450 normally ~/.fetchmailrc) and {user} is the username which is used to
1451 log on to the mail server. This header can be used to make filtering
1452 email where no useful header information is available and you want mail
1453 from different accounts sorted into different mailboxes (this could,
1454 for example, occur if you have an account on the same server running a
1455 mailing list, and are subscribed to the list using that account). The
1456 default is not adding any such header. In .fetchmailrc, this is called
1457 'tracepolls'.
1458
1461 The protocols fetchmail uses to talk to mailservers are next to bullet‐
1462 proof. In normal operation forwarding to port 25, no message is ever
1463 deleted (or even marked for deletion) on the host until the SMTP lis‐
1464 tener on the client side has acknowledged to fetchmail that the message
1465 has been either accepted for delivery or rejected due to a spam block.
1466 When forwarding to an MDA, however, there is more possibility of error.
1468 Some MDAs are 'safe' and reliably return a nonzero status on any deliv‐
1469 ery error, even one due to temporary resource limits. The maildrop(1)
1470 program is like this; so are most programs designed as mail transport
1471 agents, such as sendmail(1), including the sendmail wrapper of Postfix
1472 and exim(1). These programs give back a reliable positive acknowledge‐
1473 ment and can be used with the mda option with no risk of mail loss.
1474 Unsafe MDAs, though, may return 0 even on delivery failure. If this
1475 happens, you will lose mail.
1476 The normal mode of fetchmail is to try to download only 'new' messages,
1478 leaving untouched (and undeleted) messages you have already read
1479 directly on the server (or fetched with a previous fetchmail --keep).
1480 But you may find that messages you've already read on the server are
1481 being fetched (and deleted) even when you don't specify --all. There
1482 are several reasons this can happen.
1483 One could be that you're using POP2. The POP2 protocol includes no
1485 representation of 'new' or 'old' state in messages, so fetchmail must
1486 treat all messages as new all the time. But POP2 is obsolete, so this
1487 is unlikely.
1488 A potential POP3 problem might be servers that insert messages in the
1490 middle of mailboxes (some VMS implementations of mail are rumored to do
1491 this). The fetchmail code assumes that new messages are appended to
1492 the end of the mailbox; when this is not true it may treat some old
1493 messages as new and vice versa. Using UIDL whilst setting fastuidl 0
1494 might fix this, otherwise, consider switching to IMAP.
1495 Yet another POP3 problem is that if they can't make tempfiles in the
1497 user's home directory, some POP3 servers will hand back an undocumented
1498 response that causes fetchmail to spuriously report "No mail".
1499 The IMAP code uses the presence or absence of the server flag \Seen to
1501 decide whether or not a message is new. This isn't the right thing to
1502 do, fetchmail should check the UIDVALIDITY and use UID, but it doesn't
1503 do that yet. Under Unix, it counts on your IMAP server to notice the
1504 BSD-style Status flags set by mail user agents and set the \Seen flag
1505 from them when appropriate. All Unix IMAP servers we know of do this,
1506 though it's not specified by the IMAP RFCs. If you ever trip over a
1507 server that doesn't, the symptom will be that messages you have already
1508 read on your host will look new to the server. In this (unlikely)
1509 case, only messages you fetched with fetchmail --keep will be both
1510 undeleted and marked old.
1511 In ETRN and ODMR modes, fetchmail does not actually retrieve messages;
1513 instead, it asks the server's SMTP listener to start a queue flush to
1514 the client via SMTP. Therefore it sends only undelivered messages.
1515
1518 Many SMTP listeners allow administrators to set up 'spam filters' that
1519 block unsolicited email from specified domains. A MAIL FROM or DATA
1520 line that triggers this feature will elicit an SMTP response which
1521 (unfortunately) varies according to the listener.
1522 Newer versions of sendmail return an error code of 571.
1524 According to RFC2821, the correct thing to return in this situation is
1526 550 "Requested action not taken: mailbox unavailable" (the draft adds
1527 "[E.g., mailbox not found, no access, or command rejected for policy
1528 reasons].").
1529 Older versions of the exim MTA return 501 "Syntax error in parameters
1531 or arguments".
1532 The postfix MTA runs 554 as an antispam response.
1534 Zmailer may reject code with a 500 response (followed by an enhanced
1536 status code that contains more information).
1537 Return codes which fetchmail treats as antispam responses and discards
1539 the message can be set with the 'antispam' option. This is one of the
1540 only three circumstance under which fetchmail ever discards mail (the
1541 others are the 552 and 553 errors described below, and the suppression
1542 of multidropped messages with a message-ID already seen).
1543 If fetchmail is fetching from an IMAP server, the antispam response
1545 will be detected and the message rejected immediately after the headers
1546 have been fetched, without reading the message body. Thus, you won't
1547 pay for downloading spam message bodies.
1548 By default, the list of antispam responses is empty.
1550 If the spambounce global option is on, mail that is spam-blocked trig‐
1552 gers an RFC1892/RFC1894 bounce message informing the originator that we
1553 do not accept mail from it. See also BUGS.
1554
1557 Besides the spam-blocking described above, fetchmail takes special
1558 actions — that may be modified by the --softbounce option — on the fol‐
1559 lowing SMTP/ESMTP error response codes
1560 452 (insufficient system storage)
1562 Leave the message in the server mailbox for later retrieval.
1563 552 (message exceeds fixed maximum message size)
1565 Delete the message from the server. Send bounce-mail to the orig‐
1566 inator.
1567 553 (invalid sending domain)
1569 Delete the message from the server. Don't even try to send
1570 bounce-mail to the originator.
1571 Other errors greater or equal to 500 trigger bounce mail back to the
1573 originator, unless suppressed by --softbounce. See also BUGS.
1574
1577 The preferred way to set up fetchmail is to write a .fetchmailrc file
1578 in your home directory (you may do this directly, with a text editor,
1579 or indirectly via fetchmailconf). When there is a conflict between the
1580 command-line arguments and the arguments in this file, the command-line
1581 arguments take precedence.
1582 To protect the security of your passwords, your ~/.fetchmailrc may not
1584 normally have more than 0700 (u=rwx,g=,o=) permissions; fetchmail will
1585 complain and exit otherwise (this check is suppressed when --version is
1586 on).
1587 You may read the .fetchmailrc file as a list of commands to be executed
1589 when fetchmail is called with no arguments.
1590 Run Control Syntax
1592 Comments begin with a '#' and extend through the end of the line. Oth‐
1593 erwise the file consists of a series of server entries or global option
1594 statements in a free-format, token-oriented syntax.
1595 There are four kinds of tokens: grammar keywords, numbers (i.e. decimal
1597 digit sequences), unquoted strings, and quoted strings. A quoted
1598 string is bounded by double quotes and may contain whitespace (and
1599 quoted digits are treated as a string). Note that quoted strings will
1600 also contain line feed characters if they run across two or more lines,
1601 unless you use a backslash to join lines (see below). An unquoted
1602 string is any whitespace-delimited token that is neither numeric,
1603 string quoted nor contains the special characters ',', ';', ':', or
1604 '='.
1605 Any amount of whitespace separates tokens in server entries, but is
1607 otherwise ignored. You may use backslash escape sequences (\n for LF,
1608 \t for HT, \b for BS, \r for CR, \nnn for decimal (where nnn cannot
1609 start with a 0), \0ooo for octal, and \xhh for hex) to embed non-print‐
1610 able characters or string delimiters in strings. In quoted strings, a
1611 backslash at the very end of a line will cause the backslash itself and
1612 the line feed (LF or NL, new line) character to be ignored, so that you
1613 can wrap long strings. Without the backslash at the line end, the line
1614 feed character would become part of the string.
1615 Warning: while these resemble C-style escape sequences, they are not
1617 the same. fetchmail only supports these eight styles. C supports more
1618 escape sequences that consist of backslash (\) and a single character,
1619 but does not support decimal codes and does not require the leading 0
1620 in octal notation. Example: fetchmail interprets \233 the same as \xE9
1621 (Latin small letter e with acute), where C would interpret \233 as
1622 octal 0233 = \x9B (CSI, control sequence introducer).
1623 Each server entry consists of one of the keywords 'poll' or 'skip',
1625 followed by a server name, followed by server options, followed by any
1626 number of user (or username) descriptions, followed by user options.
1627 Note: the most common cause of syntax errors is mixing up user and
1628 server options or putting user options before the user descriptions.
1629 For backward compatibility, the word 'server' is a synonym for 'poll'.
1631 You can use the noise keywords 'and', 'with', 'has', 'wants', and
1633 'options' anywhere in an entry to make it resemble English. They're
1634 ignored, but but can make entries much easier to read at a glance. The
1635 punctuation characters ':', ';' and ',' are also ignored.
1636 Poll vs. Skip
1638 The 'poll' verb tells fetchmail to query this host when it is run with
1639 no arguments. The 'skip' verb tells fetchmail not to poll this host
1640 unless it is explicitly named on the command line. (The 'skip' verb
1641 allows you to experiment with test entries safely, or easily disable
1642 entries for hosts that are temporarily down.)
1643 Keyword/Option Summary
1645 Here are the legal options. Keyword suffixes enclosed in square brack‐
1646 ets are optional. Those corresponding to short command-line options
1647 are followed by '-' and the appropriate option letter. If option is
1648 only relevant to a single mode of operation, it is noted as 's' or 'm'
1649 for singledrop- or multidrop-mode, respectively.
1650 Here are the legal global options:
1652 Keyword Opt Mode Function
1655 ────────────────────────────────────────────────────────────────────
1656 set daemon -d Set a background poll interval in
1657 seconds.
1658 set postmaster Give the name of the last-resort
1659 mail recipient (default: user run‐
1660 ning fetchmail, "postmaster" if
1661 run by the root user)
1662 set bouncemail Direct error mail to the sender
1663 (default)
1664 set no bouncemail Direct error mail to the local
1665 postmaster (as per the 'postmas‐
1666 ter' global option above).
1667 set no spambounce Do not bounce spam-blocked mail
1668 (default).
1669 set spambounce Bounce blocked spam-blocked mail
1670 (as per the 'antispam' user
1671 option) back to the destination as
1672 indicated by the 'bouncemail'
1673 global option. Warning: Do not
1674 use this to bounce spam back to
1675 the sender - most spam is sent
1676 with false sender address and thus
1677 this option hurts innocent
1678 bystanders.
1679 set no softbounce Delete permanently undeliverable
1680 mail. It is recommended to use
1681 this option if the configuration
1682 has been thoroughly tested.
1683 set softbounce Keep permanently undeliverable
1684 mail as though a temporary error
1685 had occurred (default).
1686 set logfile -L Name of a file to append error and
1687 status messages to. Only effec‐
1688 tive in daemon mode and if fetch‐
1689 mail detaches. If effective,
1690 overrides set syslog.
1691 set idfile -i Name of the file to store UID
1692 lists in.
1693 set syslog Do error logging through sys‐
1694 log(3). May be overridden by set
1695 logfile.
1696 set no syslog Turn off error logging through
1697 syslog(3). (default)
1698 set properties String value that is ignored by
1699 fetchmail (may be used by exten‐
1700 sion scripts).
1701 Here are the legal server options:
1703 Keyword Opt Mode Function
1706 ─────────────────────────────────────────────────────────────────
1707 via Specify DNS name of mailserver,
1708 overriding poll name
1709 proto[col] -p Specify protocol (case insensi‐
1710 tive): POP2, POP3, IMAP, APOP,
1711 KPOP
1712 local[domains] m Specify domain(s) to be regarded
1713 as local
1714 port Specify TCP/IP service port (obso‐
1715 lete, use 'service' instead).
1716 service -P Specify service name (a numeric
1717 value is also allowed and consid‐
1718 ered a TCP/IP port number).
1719 auth[enticate] Set authentication type (default
1722 'any')
1723 timeout -t Server inactivity timeout in sec‐
1724 onds (default 300)
1725 envelope -E m Specify envelope-address header
1726 name
1727 no envelope m Disable looking for envelope
1728 address
1729 qvirtual -Q m Qmail virtual domain prefix to
1730 remove from user name
1731 aka m Specify alternate DNS names of
1732 mailserver
1733 interface -I specify IP interface(s) that must
1734 be up for server poll to take
1735 place
1736 monitor -M Specify IP address to monitor for
1737 activity
1738 plugin Specify command through which to
1739 make server connections.
1740 plugout Specify command through which to
1741 make listener connections.
1742 dns m Enable DNS lookup for multidrop
1743 (default)
1744 no dns m Disable DNS lookup for multidrop
1745 checkalias m Do comparison by IP address for
1746 multidrop
1747 no checkalias m Do comparison by name for mul‐
1748 tidrop (default)
1749 uidl -U Force POP3 to use client-side
1750 UIDLs (recommended)
1751 no uidl Turn off POP3 use of client-side
1752 UIDLs (default)
1753 interval Only check this site every N poll
1754 cycles; N is a numeric argument.
1755 tracepolls Add poll tracing information to
1756 the Received header
1757 principal Set Kerberos principal (only use‐
1758 ful with IMAP and kerberos)
1759 esmtpname Set name for RFC2554 authentica‐
1760 tion to the ESMTP server.
1761 esmtppassword Set password for RFC2554 authenti‐
1762 cation to the ESMTP server.
1763 bad-header How to treat messages with a bad
1764 header. Can be reject (default) or
1765 accept.
1766 Here are the legal user descriptions and options:
1768 Keyword Opt Mode Function
1771 ───────────────────────────────────────────────────────────────────────
1772 user[name] -u This is the user description and
1773 must come first after server
1774 description and after possible
1775 server options, and before user
1776 options.
1777 It sets the remote user name if by
1778 itself or followed by 'there', or
1779 the local user name if followed by
1780 'here'.
1781 is Connect local and remote user
1782 names
1783 to Connect local and remote user
1784 names
1785 pass[word] Specify remote account password
1786 ssl Connect to server over the speci‐
1787 fied base protocol using SSL
1788 encryption
1789 sslcert Specify file for client side pub‐
1791 lic SSL certificate
1792 sslcertck Enable strict certificate checking
1793 and abort connection on failure.
1794 Default only since fetchmail
1795 v6.4.0.
1796 no sslcertck Disable strict certificate check‐
1797 ing and permit connections to con‐
1798 tinue on failed verification. Dis‐
1799 couraged. Should only be used
1800 together with sslfingerprint.
1801 sslcertfile Specify file with trusted CA cer‐
1802 tificates
1803 sslcertpath Specify c_rehash-ed directory with
1804 trusted CA certificates.
1805 sslfingerprint <HASH> Specify the expected server certi‐
1806 ficat finger print. Fetchmail will
1807 disconnect and log an error if it
1808 does not match.
1809 sslkey Specify file for client side pri‐
1810 vate SSL key
1811 sslproto Force ssl protocol for connection
1812 folder -r Specify remote folder to query
1813 smtphost -S Specify smtp host(s) to forward to
1814 fetchdomains m Specify domains for which mail
1815 should be fetched
1816 smtpaddress -D Specify the domain to be put in
1817 RCPT TO lines
1818 smtpname Specify the user and domain to be
1819 put in RCPT TO lines
1820 antispam -Z Specify what SMTP returns are
1821 interpreted as spam-policy blocks
1822 mda -m Specify MDA for local delivery
1823 bsmtp Specify BSMTP batch file to append
1824 to
1825 preconnect Command to be executed before each
1826 connection
1827 postconnect Command to be executed after each
1828 connection
1829 keep -k Don't delete seen messages from
1830 server (for POP3, uidl is recom‐
1831 mended)
1832 flush -F Flush all seen messages before
1833 querying (DANGEROUS)
1834 limitflush Flush all oversized messages
1835 before querying
1836 fetchall -a Fetch all messages whether seen or
1837 not
1838 rewrite Rewrite destination addresses for
1839 reply (default)
1840 stripcr Strip carriage returns from ends
1841 of lines
1842 forcecr Force carriage returns at ends of
1843 lines
1844 pass8bits Force BODY=8BITMIME to ESMTP lis‐
1845 tener
1846 dropstatus Strip Status and X-Mozilla-Status
1847 lines out of incoming mail
1848 dropdelivered Strip Delivered-To lines out of
1849 incoming mail
1850 mimedecode Convert quoted-printable to 8-bit
1851 in MIME messages
1852 idle Idle waiting for new messages
1853 after each poll (IMAP only)
1854 no keep -K Delete seen messages from server
1855 (default)
1856 no flush Don't flush all seen messages
1857 before querying (default)
1858 no fetchall Retrieve only new messages
1860 (default)
1861 no rewrite Don't rewrite headers
1862 no stripcr Don't strip carriage returns
1863 (default)
1864 no forcecr Don't force carriage returns at
1865 EOL (default)
1866 no pass8bits Don't force BODY=8BITMIME to ESMTP
1867 listener (default)
1868 no dropstatus Don't drop Status headers
1869 (default)
1870 no dropdelivered Don't drop Delivered-To headers
1871 (default)
1872 no mimedecode Don't convert quoted-printable to
1873 8-bit in MIME messages (default)
1874 no idle Don't idle waiting for new mes‐
1875 sages after each poll (IMAP only)
1876 limit -l Set message size limit
1877 warnings -w Set message size warning interval
1878 batchlimit -b Max # messages to forward in sin‐
1879 gle connect
1880 fetchlimit -B Max # messages to fetch in single
1881 connect
1882 fetchsizelimit Max # message sizes to fetch in
1883 single transaction
1884 fastuidl Use binary search for first unseen
1885 message (POP3 only)
1886 expunge -e Perform an expunge on every #th
1887 message (IMAP and POP3 only)
1888 properties String value is ignored by fetch‐
1889 mail (may be used by extension
1890 scripts)
1891 All user options must begin with a user description (user or username
1893 option) and follow all server descriptions and options.
1894 In the .fetchmailrc file, the 'envelope' string argument may be pre‐
1896 ceded by a whitespace-separated number. This number, if specified, is
1897 the number of such headers to skip over (that is, an argument of 1
1898 selects the second header of the given type). This is sometime useful
1899 for ignoring bogus envelope headers created by an ISP's local delivery
1900 agent or internal forwards (through mail inspection systems, for
1901 instance).
1902 Keywords Not Corresponding To Option Switches
1904 The 'folder' and 'smtphost' options (unlike their command-line equiva‐
1905 lents) can take a space- or comma-separated list of names following
1906 them.
1907 All options correspond to the obvious command-line arguments, except
1909 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1910 'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1911 'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1912 'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus', 'dropdeliv‐
1913 ered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle', and 'no
1914 envelope'.
1915 The 'via' option is for if you want to have more than one configuration
1917 pointing at the same site. If it is present, the string argument will
1918 be taken as the actual DNS name of the mailserver host to query. This
1919 will override the argument of poll, which can then simply be a distinct
1920 label for the configuration (e.g. what you would give on the command
1921 line to explicitly query this host).
1922 The 'interval' option (which takes a numeric argument) allows you to
1924 poll a server less frequently than the basic poll interval. If you say
1925 'interval N' the server this option is attached to will only be queried
1926 every N poll intervals.
1927 Singledrop vs. Multidrop options
1929 Please ensure you read the section titled THE USE AND ABUSE OF MUL‐
1930 TIDROP MAILBOXES if you intend to use multidrop mode.
1931 The 'is' or 'to' keywords associate the following local (client)
1933 name(s) (or server-name to client-name mappings separated by =) with
1934 the mailserver user name in the entry. If an is/to list has '*' as its
1935 last name, unrecognized names are simply passed through. Note that
1936 until fetchmail version 6.3.4 inclusively, these lists could only con‐
1937 tain local parts of user names (fetchmail would only look at the part
1938 before the @ sign). fetchmail versions 6.3.5 and newer support full
1939 addresses on the left hand side of these mappings, and they take prece‐
1940 dence over any 'localdomains', 'aka', 'via' or similar mappings.
1941 A single local name can be used to support redirecting your mail when
1943 your username on the client machine is different from your name on the
1944 mailserver. When there is only a single local name, mail is forwarded
1945 to that local username regardless of the message's Received, To, Cc,
1946 and Bcc headers. In this case, fetchmail never does DNS lookups.
1947 When there is more than one local name (or name mapping), fetchmail
1949 looks at the envelope header, if configured, and otherwise at the
1950 Received, To, Cc, and Bcc headers of retrieved mail (this is 'multidrop
1951 mode'). It looks for addresses with hostname parts that match your
1952 poll name or your 'via', 'aka' or 'localdomains' options, and usually
1953 also for hostname parts which DNS tells it are aliases of the
1954 mailserver. See the discussion of 'dns', 'checkalias', 'localdomains',
1955 and 'aka' for details on how matching addresses are handled.
1956 If fetchmail cannot match any mailserver usernames or localdomain
1958 addresses, the mail will be bounced. Normally it will be bounced to
1959 the sender, but if the 'bouncemail' global option is off, the mail will
1960 go to the local postmaster instead. (see the 'postmaster' global
1961 option). See also BUGS.
1962 The 'dns' option (normally on) controls the way addresses from mul‐
1964 tidrop mailboxes are checked. On, it enables logic to check each host
1965 address that does not match an 'aka' or 'localdomains' declaration by
1966 looking it up with DNS. When a mailserver username is recognized
1967 attached to a matching hostname part, its local mapping is added to the
1968 list of local recipients.
1969 The 'checkalias' option (normally off) extends the lookups performed by
1971 the 'dns' keyword in multidrop mode, providing a way to cope with
1972 remote MTAs that identify themselves using their canonical name, while
1973 they're polled using an alias. When such a server is polled, checks to
1974 extract the envelope address fail, and fetchmail reverts to delivery
1975 using the To/Cc/Bcc headers (See below 'Header vs. Envelope
1976 addresses'). Specifying this option instructs fetchmail to retrieve
1977 all the IP addresses associated with both the poll name and the name
1978 used by the remote MTA and to do a comparison of the IP addresses.
1979 This comes in handy in situations where the remote server undergoes
1980 frequent canonical name changes, that would otherwise require modifica‐
1981 tions to the rcfile. 'checkalias' has no effect if 'no dns' is speci‐
1982 fied in the rcfile.
1983 The 'aka' option is for use with multidrop mailboxes. It allows you to
1985 pre-declare a list of DNS aliases for a server. This is an optimiza‐
1986 tion hack that allows you to trade space for speed. When fetchmail,
1987 while processing a multidrop mailbox, grovels through message headers
1988 looking for names of the mailserver, pre-declaring common ones can save
1989 it from having to do DNS lookups. Note: the names you give as argu‐
1990 ments to 'aka' are matched as suffixes -- if you specify (say) 'aka
1991 netaxs.com', this will match not just a hostname netaxs.com, but any
1992 hostname that ends with '.netaxs.com'; such as (say) pop3.netaxs.com
1993 and mail.netaxs.com.
1994 The 'localdomains' option allows you to declare a list of domains which
1996 fetchmail should consider local. When fetchmail is parsing address
1997 lines in multidrop modes, and a trailing segment of a host name matches
1998 a declared local domain, that address is passed through to the listener
1999 or MDA unaltered (local-name mappings are not applied).
2000 If you are using 'localdomains', you may also need to specify 'no enve‐
2002 lope', which disables fetchmail's normal attempt to deduce an envelope
2003 address from the Received line or X-Envelope-To header or whatever
2004 header has been previously set by 'envelope'. If you set 'no envelope'
2005 in the defaults entry it is possible to undo that in individual entries
2006 by using 'envelope <string>'. As a special case, 'envelope "Received"'
2007 restores the default parsing of Received lines.
2008 The password option requires a string argument, which is the password
2010 to be used with the entry's server.
2011 The 'preconnect' keyword allows you to specify a shell command to be
2013 executed just before each time fetchmail establishes a mailserver con‐
2014 nection. This may be useful if you are attempting to set up secure POP
2015 connections with the aid of ssh(1). If the command returns a nonzero
2016 status, the poll of that mailserver will be aborted.
2017 Similarly, the 'postconnect' keyword similarly allows you to specify a
2019 shell command to be executed just after each time a mailserver connec‐
2020 tion is taken down.
2021 The 'forcecr' option controls whether lines terminated by LF only are
2023 given CRLF termination before forwarding. Strictly speaking RFC821
2024 requires this, but few MTAs enforce the requirement so this option is
2025 normally off (only one such MTA, qmail, is in significant use at time
2026 of writing).
2027 The 'stripcr' option controls whether carriage returns are stripped out
2029 of retrieved mail before it is forwarded. It is normally not necessary
2030 to set this, because it defaults to 'on' (CR stripping enabled) when
2031 there is an MDA declared but 'off' (CR stripping disabled) when for‐
2032 warding is via SMTP. If 'stripcr' and 'forcecr' are both on, 'stripcr'
2033 will override.
2034 The 'pass8bits' option exists to cope with Microsoft mail programs that
2036 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
2037 this option off (the default) and such a header present, fetchmail
2038 declares BODY=7BIT to an ESMTP-capable listener; this causes problems
2039 for messages actually using 8-bit ISO or KOI-8 character sets, which
2040 will be garbled by having the high bits of all characters stripped. If
2041 'pass8bits' is on, fetchmail is forced to declare BODY=8BITMIME to any
2042 ESMTP-capable listener. If the listener is 8-bit-clean (as all the
2043 major ones now are) the right thing will probably result.
2044 The 'dropstatus' option controls whether nonempty Status and X-Mozilla-
2046 Status lines are retained in fetched mail (the default) or discarded.
2047 Retaining them allows your MUA to see what messages (if any) were
2048 marked seen on the server. On the other hand, it can confuse some new-
2049 mail notifiers, which assume that anything with a Status line in it has
2050 been seen. (Note: the empty Status lines inserted by some buggy POP
2051 servers are unconditionally discarded.)
2052 The 'dropdelivered' option controls whether Delivered-To headers will
2054 be kept in fetched mail (the default) or discarded. These headers are
2055 added by Qmail and Postfix mailservers in order to avoid mail loops but
2056 may get in your way if you try to "mirror" a mailserver within the same
2057 domain. Use with caution.
2058 The 'mimedecode' option controls whether MIME messages using the
2060 quoted-printable encoding are automatically converted into pure 8-bit
2061 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean lis‐
2062 tener (that includes all of the major MTAs like sendmail), then this
2063 will automatically convert quoted-printable message headers and data
2064 into 8-bit data, making it easier to understand when reading mail. If
2065 your e-mail programs know how to deal with MIME messages, then this
2066 option is not needed. The mimedecode option is off by default, because
2067 doing RFC2047 conversion on headers throws away character-set informa‐
2068 tion and can lead to bad results if the encoding of the headers differs
2069 from the body encoding.
2070 The 'idle' option is intended to be used with IMAP servers supporting
2072 the RFC2177 IDLE command extension, but does not strictly require it.
2073 If it is enabled, and fetchmail detects that IDLE is supported, an IDLE
2074 will be issued at the end of each poll. This will tell the IMAP server
2075 to hold the connection open and notify the client when new mail is
2076 available. If IDLE is not supported, fetchmail will simulate it by
2077 periodically issuing NOOP. If you need to poll a link frequently, IDLE
2078 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
2079 sequences. On the other hand, an IDLE connection will eat almost all of
2080 your fetchmail's time, because it will never drop the connection and
2081 allow other polls to occur unless the server times out the IDLE. It
2082 also doesn't work with multiple folders; only the first folder will
2083 ever be polled.
2084 The 'properties' option is an extension mechanism. It takes a string
2087 argument, which is ignored by fetchmail itself. The string argument
2088 may be used to store configuration information for scripts which
2089 require it. In particular, the output of '--configdump' option will
2090 make properties associated with a user entry readily available to a
2091 Python script.
2092 Miscellaneous Run Control Options
2094 The words 'here' and 'there' have useful English-like significance.
2095 Normally 'user eric is esr' would mean that mail for the remote user
2096 'eric' is to be delivered to 'esr', but you can make this clearer by
2097 saying 'user eric there is esr here', or reverse it by saying 'user esr
2098 here is eric there'
2099 Legal protocol identifiers for use with the 'protocol' keyword are:
2101 auto (or AUTO) (legacy, to be removed from future release)
2103 pop2 (or POP2) (legacy, to be removed from future release)
2104 pop3 (or POP3)
2105 sdps (or SDPS)
2106 imap (or IMAP)
2107 apop (or APOP)
2108 kpop (or KPOP)
2109 Legal authentication types are 'any', 'password', 'kerberos', 'ker‐
2112 beros_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn' (only
2113 for POP3), 'ntlm', 'ssh', 'external' (only IMAP). The 'password' type
2114 specifies authentication by normal transmission of a password (the
2115 password may be plain text or subject to protocol-specific encryption
2116 as in CRAM-MD5); 'kerberos' tells fetchmail to try to get a Kerberos
2117 ticket at the start of each query instead, and send an arbitrary string
2118 as the password; and 'gssapi' tells fetchmail to use GSSAPI authentica‐
2119 tion. See the description of the 'auth' keyword for more.
2120 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
2122 authentication. These defaults may be overridden by later options.
2123 There are some global option statements: 'set logfile' followed by a
2125 string sets the same global specified by --logfile. A command-line
2126 --logfile option will override this. Note that --logfile is only effec‐
2127 tive if fetchmail detaches itself from the terminal and the logfile
2128 already exists before fetchmail is run, and it overrides --syslog in
2129 this case. Also, 'set daemon' sets the poll interval as --daemon does.
2130 This can be overridden by a command-line --daemon option; in particular
2131 --daemon 0 can be used to force foreground operation. The 'set postmas‐
2132 ter' statement sets the address to which multidrop mail defaults if
2133 there are no local matches. Finally, 'set syslog' sends log messages
2134 to syslogd(8).
2135
2138 Fetchmail crashing
2139 There are various ways in that fetchmail may "crash", i. e. stop opera‐
2140 tion suddenly and unexpectedly. A "crash" usually refers to an error
2141 condition that the software did not handle by itself. A well-known
2142 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
2143 just "segfault" for short. These can be caused by hardware or by soft‐
2144 ware problems. Software-induced segfaults can usually be reproduced
2145 easily and in the same place, whereas hardware-induced segfaults can go
2146 away if the computer is rebooted, or powered off for a few hours, and
2147 can happen in random locations even if you use the software the same
2148 way.
2149 For solving hardware-induced segfaults, find the faulty component and
2151 repair or replace it. The Sig11 FAQ ⟨http://www.bitwizard.nl/sig11/⟩
2152 may help you with details.
2153 For solving software-induced segfaults, the developers may need a
2155 "stack backtrace".
2156 Enabling fetchmail core dumps
2159 By default, fetchmail suppresses core dumps as these might contain
2160 passwords and other sensitive information. For debugging fetchmail
2161 crashes, obtaining a "stack backtrace" from a core dump is often the
2162 quickest way to solve the problem, and when posting your problem on a
2163 mailing list, the developers may ask you for a "backtrace".
2164 1. To get useful backtraces, fetchmail needs to be installed without
2166 getting stripped of its compilation symbols. Unfortunately, most
2167 binary packages that are installed are stripped, and core files from
2168 symbol-stripped programs are worthless. So you may need to recompile
2169 fetchmail. On many systems, you can type
2170 file `which fetchmail`
2172 to find out if fetchmail was symbol-stripped or not. If yours was
2174 unstripped, fine, proceed, if it was stripped, you need to recompile
2175 the source code first. You do not usually need to install fetchmail in
2176 order to debug it.
2177 2. The shell environment that starts fetchmail needs to enable core
2179 dumps. The key is the "maximum core (file) size" that can usually be
2180 configured with a tool named "limit" or "ulimit". See the documentation
2181 for your shell for details. In the popular bash shell, "ulimit -Sc
2182 unlimited" will allow the core dump.
2183 3. You need to tell fetchmail, too, to allow core dumps. To do this,
2185 run fetchmail with the -d0 -v options. It is often easier to also add
2186 --nosyslog -N as well.
2187 Finally, you need to reproduce the crash. You can just start fetchmail
2189 from the directory where you compiled it by typing ./fetchmail, so the
2190 complete command line will start with ./fetchmail -Nvd0 --nosyslog and
2191 perhaps list your other options.
2192 After the crash, run your debugger to obtain the core dump. The debug‐
2194 ger will often be GNU GDB, you can then type (adjust paths as neces‐
2195 sary) gdb ./fetchmail fetchmail.core and then, after GDB has started up
2196 and read all its files, type backtrace full, save the output (copy &
2197 paste will do, the backtrace will be read by a human) and then type
2198 quit to leave gdb. Note: on some systems, the core files have differ‐
2199 ent names, they might contain a number instead of the program name, or
2200 number and name, but it will usually have "core" as part of their name.
2201
2204 When trying to determine the originating address of a message, fetch‐
2205 mail looks through headers in the following order:
2206 Return-Path:
2208 Resent-Sender: (ignored if it doesn't contain an @ or !)
2209 Sender: (ignored if it doesn't contain an @ or !)
2210 Resent-From:
2211 From:
2212 Reply-To:
2213 Apparently-From:
2214 The originating address is used for logging, and to set the MAIL FROM
2216 address when forwarding to SMTP. This order is intended to cope grace‐
2217 fully with receiving mailing list messages in multidrop mode. The
2218 intent is that if a local address doesn't exist, the bounce message
2219 won't be returned blindly to the author or to the list itself, but
2220 rather to the list manager (which is less annoying).
2221 In multidrop mode, destination headers are processed as follows: First,
2223 fetchmail looks for the header specified by the 'envelope' option in
2224 order to determine the local recipient address. If the mail is
2225 addressed to more than one recipient, the Received line won't contain
2226 any information regarding recipient addresses.
2227 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2229 lines. If they exist, they should contain the final recipients and
2230 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
2231 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2232 looked for. (The presence of a Resent-To: is taken to imply that the
2233 person referred by the To: address has already received the original
2234 copy of the mail.)
2235
2238 Note that although there are password declarations in a good many of
2239 the examples below, this is mainly for illustrative purposes. We rec‐
2240 ommend stashing account/password pairs in your $HOME/.netrc file, where
2241 they can be used not just by fetchmail but by ftp(1) and other pro‐
2242 grams.
2243 The basic format is:
2245 poll SERVERNAME protocol PROTOCOL username NAME password PASS‐
2248 WORD
2249 Example:
2252 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2255 Or, using some abbreviations:
2258 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2261 Multiple servers may be listed:
2264 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2267 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2268 Here's the same version with more whitespace and some noise words:
2271 poll pop.provider.net proto pop3
2274 user "jsmith", with password secret1, is "jsmith" here;
2275 poll other.provider.net proto pop2:
2276 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2277 If you need to include whitespace in a parameter string or start the
2280 latter with a number, enclose the string in double quotes. Thus:
2281 poll mail.provider.net with proto pop3:
2284 user "jsmith" there has password "4u but u can't krak this"
2285 is jws here and wants mda "/bin/mail"
2286 You may have an initial server description headed by the keyword
2289 'defaults' instead of 'poll' followed by a name. Such a record is
2290 interpreted as defaults for all queries to use. It may be overwritten
2291 by individual server descriptions. So, you could write:
2292 defaults proto pop3
2295 user "jsmith"
2296 poll pop.provider.net
2297 pass "secret1"
2298 poll mail.provider.net
2299 user "jjsmith" there has password "secret2"
2300 It's possible to specify more than one user per server. The 'user'
2303 keyword leads off a user description, and every user specification in a
2304 multi-user entry must include it. Here's an example:
2305 poll pop.provider.net proto pop3 port 3111
2308 user "jsmith" with pass "secret1" is "smith" here
2309 user jones with pass "secret2" is "jjones" here keep
2310 This associates the local username 'smith' with the pop.provider.net
2313 username 'jsmith' and the local username 'jjones' with the
2314 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2315 server after download.
2316 Here's what a simple retrieval configuration for a multidrop mailbox
2319 looks like:
2320 poll pop.provider.net:
2323 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2324 This says that the mailbox of account 'maildrop' on the server is a
2327 multidrop box, and that messages in it should be parsed for the server
2328 user names 'golux', 'hurkle', and 'snark'. It further specifies that
2329 'golux' and 'snark' have the same name on the client as on the server,
2330 but mail for server user 'hurkle' should be delivered to client user
2331 'happy'.
2332 Note that fetchmail, until version 6.3.4, did NOT allow full
2335 user@domain specifications here, these would never match. Fetchmail
2336 6.3.5 and newer support user@domain specifications on the left-hand
2337 side of a user mapping.
2338 Here's an example of another kind of multidrop connection:
2341 poll pop.provider.net localdomains loonytoons.org toons.org
2344 envelope X-Envelope-To
2345 user maildrop with pass secret1 to * here
2346 This also says that the mailbox of account 'maildrop' on the server is
2349 a multidrop box. It tells fetchmail that any address in the loony‐
2350 toons.org or toons.org domains (including sub-domain addresses like
2351 'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2352 listener without modification. Be careful of mail loops if you do
2353 this!
2354 Here's an example configuration using ssh and the plugin option. The
2357 queries are made directly on the stdin and stdout of imapd via ssh.
2358 Note that in this setup, IMAP authentication can be skipped.
2359 poll mailhost.net with proto imap:
2362 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2363 user esr is esr here
2364
2367 Use the multiple-local-recipients feature with caution -- it can bite.
2368 All multidrop features are ineffective in ETRN and ODMR modes.
2369 Also, note that in multidrop mode duplicate mails are suppressed. A
2371 piece of mail is considered duplicate if it has the same message-ID as
2372 the message immediately preceding and more than one addressee. Such
2373 runs of messages may be generated when copies of a message addressed to
2374 multiple users are delivered to a multidrop box.
2375 Header vs. Envelope addresses
2378 The fundamental problem is that by having your mailserver toss several
2379 peoples' mail in a single maildrop box, you may have thrown away poten‐
2380 tially vital information about who each piece of mail was actually
2381 addressed to (the 'envelope address', as opposed to the header
2382 addresses in the RFC822 To/Cc headers - the Bcc is not available at the
2383 receiving end). This 'envelope address' is the address you need in
2384 order to reroute mail properly.
2385 Sometimes fetchmail can deduce the envelope address. If the mailserver
2387 MTA is sendmail and the item of mail had just one recipient, the MTA
2388 will have written a 'by/for' clause that gives the envelope addressee
2389 into its Received header. But this doesn't work reliably for other
2390 MTAs, nor if there is more than one recipient. By default, fetchmail
2391 looks for envelope addresses in these lines; you can restore this
2392 default with -E "Received" or 'envelope Received'.
2393 As a better alternative, some SMTP listeners and/or mail servers insert
2395 a header in each message containing a copy of the envelope addresses.
2396 This header (when it exists) is often 'X-Original-To', 'Delivered-To'
2397 or 'X-Envelope-To'. Fetchmail's assumption about this can be changed
2398 with the -E or 'envelope' option. Note that writing an envelope header
2399 of this kind exposes the names of recipients (including blind-copy
2400 recipients) to all receivers of the messages, so the upstream must
2401 store one copy of the message per recipient to avoid becoming a privacy
2402 problem.
2403 Postfix, since version 2.0, writes an X-Original-To: header which con‐
2405 tains a copy of the envelope as it was received.
2406 Qmail and Postfix generally write a 'Delivered-To' header upon deliver‐
2408 ing the message to the mail spool and use it to avoid mail loops.
2409 Qmail virtual domains however will prefix the user name with a string
2410 that normally matches the user's domain. To remove this prefix you can
2411 use the -Q or 'qvirtual' option.
2412 Sometimes, unfortunately, neither of these methods works. That is the
2414 point when you should contact your ISP and ask them to provide such an
2415 envelope header, and you should not use multidrop in this situation.
2416 When they all fail, fetchmail must fall back on the contents of To/Cc
2417 headers (Bcc headers are not available - see below) to try to determine
2418 recipient addressees -- and these are unreliable. In particular, mail‐
2419 ing-list software often ships mail with only the list broadcast address
2420 in the To header.
2421 Note that a future version of fetchmail may remove To/Cc parsing!
2423 When fetchmail cannot deduce a recipient address that is local, and the
2425 intended recipient address was anyone other than fetchmail's invoking
2426 user, mail will get lost. This is what makes the multidrop feature
2427 risky without proper envelope information.
2428 A related problem is that when you blind-copy a mail message, the Bcc
2430 information is carried only as envelope address (it's removed from the
2431 headers by the sending mail server, so fetchmail can see it only if
2432 there is an X-Envelope-To header). Thus, blind-copying to someone who
2433 gets mail over a fetchmail multidrop link will fail unless the the
2434 mailserver host routinely writes X-Envelope-To or an equivalent header
2435 into messages in your maildrop.
2436 In conclusion, mailing lists and Bcc'd mail can only work if the server
2438 you're fetching from
2439 (1) stores one copy of the message per recipient in your domain and
2441 (2) records the envelope information in a special header (X-Origi‐
2443 nal-To, Delivered-To, X-Envelope-To).
2444 Good Ways To Use Multidrop Mailboxes
2447 Multiple local names can be used to administer a mailing list from the
2448 client side of a fetchmail collection. Suppose your name is 'esr', and
2449 you want to both pick up your own mail and maintain a mailing list
2450 called (say) "fetchmail-friends", and you want to keep the alias list
2451 on your client machine.
2452 On your server, you can alias 'fetchmail-friends' to 'esr'; then, in
2454 your .fetchmailrc, declare 'to esr fetchmail-friends here'. Then, when
2455 mail including 'fetchmail-friends' as a local address gets fetched, the
2456 list name will be appended to the list of recipients your SMTP listener
2457 sees. Therefore it will undergo alias expansion locally. Be sure to
2458 include 'esr' in the local alias expansion of fetchmail-friends, or
2459 you'll never see mail sent only to the list. Also be sure that your
2460 listener has the "me-too" option set (sendmail's -oXm command-line
2461 option or OXm declaration) so your name isn't removed from alias expan‐
2462 sions in messages you send.
2463 This trick is not without its problems, however. You'll begin to see
2465 this when a message comes in that is addressed only to a mailing list
2466 you do not have declared as a local name. Each such message will fea‐
2467 ture an 'X-Fetchmail-Warning' header which is generated because fetch‐
2468 mail cannot find a valid local name in the recipient addresses. Such
2469 messages default (as was described above) to being sent to the local
2470 user running fetchmail, but the program has no way to know that that's
2471 actually the right thing.
2472 Bad Ways To Abuse Multidrop Mailboxes
2475 Multidrop mailboxes and fetchmail serving multiple users in daemon mode
2476 do not mix. The problem, again, is mail from mailing lists, which typ‐
2477 ically does not have an individual recipient address on it. Unless
2478 fetchmail can deduce an envelope address, such mail will only go to the
2479 account running fetchmail (probably root). Also, blind-copied users
2480 are very likely never to see their mail at all.
2481 If you're tempted to use fetchmail to retrieve mail for multiple users
2483 from a single mail drop via POP or IMAP, think again (and reread the
2484 section on header and envelope addresses above). It would be smarter
2485 to just let the mail sit in the mailserver's queue and use fetchmail's
2486 ETRN or ODMR modes to trigger SMTP sends periodically (of course, this
2487 means you have to poll more frequently than the mailserver's expiry
2488 period). If you can't arrange this, try setting up a UUCP feed.
2489 If you absolutely must use multidrop for this purpose, make sure your
2491 mailserver writes an envelope-address header that fetchmail can see.
2492 Otherwise you will lose mail and it will come back to haunt you.
2493 Speeding Up Multidrop Checking
2496 Normally, when multiple users are declared fetchmail extracts recipient
2497 addresses as described above and checks each host part with DNS to see
2498 if it's an alias of the mailserver. If so, the name mappings described
2499 in the "to ... here" declaration are done and the mail locally deliv‐
2500 ered.
2501 This is a convenient but also slow method. To speed it up, pre-declare
2503 mailserver aliases with 'aka'; these are checked before DNS lookups are
2504 done. If you're certain your aka list contains all DNS aliases of the
2505 mailserver (and all MX names pointing at it - note this may change in a
2506 future version) you can declare 'no dns' to suppress DNS lookups
2507 entirely and only match against the aka list.
2508
2511 Support for socks4/5 is a compile time configuration option. Once com‐
2512 piled in, fetchmail will always use the socks libraries and configura‐
2513 tion on your system, there are no run-time switches in fetchmail - but
2514 you can still configure SOCKS: you can specify which SOCKS configura‐
2515 tion file is used in the SOCKS_CONF environment variable.
2516 For instance, if you wanted to bypass the SOCKS proxy altogether and
2518 have fetchmail connect directly, you could just pass
2519 SOCKS_CONF=/dev/null in the environment, for example (add your usual
2520 command line options - if any - to the end of this line):
2521 env SOCKS_CONF=/dev/null fetchmail
2523
2526 To facilitate the use of fetchmail in shell scripts, an exit status
2527 code is returned to give an indication of what occurred during a given
2528 connection.
2529 The exit codes returned by fetchmail are as follows:
2531 0 One or more messages were successfully retrieved (or, if the -c
2533 option was selected, were found waiting but not retrieved).
2534 1 There was no mail awaiting retrieval. (There may have been old
2536 mail still on the server but not selected for retrieval.) If you
2537 do not want "no mail" to be an error condition (for instance,
2538 for cron jobs), use a POSIX-compliant shell and add
2539 || [ $? -eq 1 ]
2541 to the end of the fetchmail command line, note that this leaves
2543 0 untouched, maps 1 to 0, and maps all other codes to 1. See
2544 also item #C8 in the FAQ.
2545 2 An error was encountered when attempting to open a socket to
2547 retrieve mail. If you don't know what a socket is, don't worry
2548 about it -- just treat this as an 'unrecoverable error'. This
2549 error can also be because a protocol fetchmail wants to use is
2550 not listed in /etc/services.
2551 3 The user authentication step failed. This usually means that a
2553 bad user-id, password, or APOP id was specified. Or it may mean
2554 that you tried to run fetchmail under circumstances where it did
2555 not have standard input attached to a terminal and could not
2556 prompt for a missing password.
2557 4 Some sort of fatal protocol error was detected.
2559 5 There was a syntax error in the arguments to fetchmail, or a
2561 pre- or post-connect command failed.
2562 6 The run control file had bad permissions.
2564 7 There was an error condition reported by the server. Can also
2566 fire if fetchmail timed out while waiting for the server.
2567 8 Client-side exclusion error. This means fetchmail either found
2569 another copy of itself already running, or failed in such a way
2570 that it isn't sure whether another copy is running.
2571 9 The user authentication step failed because the server responded
2573 "lock busy". Try again after a brief pause! This error is not
2574 implemented for all protocols, nor for all servers. If not
2575 implemented for your server, "3" will be returned instead, see
2576 above. May be returned when talking to qpopper or other servers
2577 that can respond with "lock busy" or some similar text contain‐
2578 ing the word "lock".
2579 10 The fetchmail run failed while trying to do an SMTP port open or
2581 transaction.
2582 11 Fatal DNS error. Fetchmail encountered an error while perform‐
2584 ing a DNS lookup at startup and could not proceed.
2585 12 BSMTP batch file could not be opened.
2587 13 Poll terminated by a fetch limit (see the --fetchlimit option).
2589 14 Server busy indication.
2591 23 Internal error. You should see a message on standard error with
2593 details.
2594 24 - 26, 28, 29
2596 These are internal codes and should not appear externally.
2597 When fetchmail queries more than one host, return status is 0 if any
2599 query successfully retrieved mail. Otherwise the returned error status
2600 is that of the last host queried.
2601
2604 ~/.fetchmailrc, $HOME/.fetchmailrc, $HOME_ETC/.fetchmailrc, $FETCHMAIL‐
2605 HOME/fetchmailrc
2606 default run control file (location can be overridden with environ‐
2607 ment variables)
2608 ~/.fetchids, $HOME/.fetchids, $HOME_ETC/.fetchids, $FETCHMAIL‐
2610 HOME/.fetchids
2611 default location of file recording last message UIDs seen per
2612 host. (location can be overridden with environment variables)
2613 ~/.fetchmail.pid, $HOME/.fetchmail.pid, $HOME_ETC/.fetchmail.pid,
2615 $FETCHMAILHOME/fetchmail.pid
2616 default location of lock file to help prevent concurrent runs
2617 (non-root mode). (location can be overridden with environment
2618 variables)
2619 ~/.netrc, $HOME/.netrc, $HOME_ETC/.netrc
2621 your FTP run control file, which (if present) will be searched for
2622 passwords as a last resort before prompting for one interactively.
2623 (location can be overridden with environment variables)
2624 /var/run/fetchmail.pid
2626 lock file to help prevent concurrent runs (root mode, Linux sys‐
2627 tems).
2628 /etc/fetchmail.pid
2630 lock file to help prevent concurrent runs (root mode, systems
2631 without /var/run).
2632
2635 FETCHMAILHOME
2636 If this environment variable is set to a valid and existing
2637 directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
2638 (the dot is missing in this case), $FETCHMAILHOME/.fetchids
2639 (keeping its dot) and $FETCHMAILHOME/fetchmail.pid (without dot)
2640 rather than from the user's home directory. The .netrc file is
2641 always looked for in the the invoking user's home directory (or
2642 $HOME_ETC) regardless of FETCHMAILHOME's setting.
2643 FETCHMAILUSER
2646 If this environment variable is set, it is used as the name of
2647 the calling user (default local name) for purposes such as mail‐
2648 ing error notifications. Otherwise, if either the LOGNAME or
2649 USER variable is correctly set (e.g. the corresponding UID
2650 matches the session user ID) then that name is used as the
2651 default local name. Otherwise getpwuid(3) must be able to
2652 retrieve a password entry for the session ID (this elaborate
2653 logic is designed to handle the case of multiple names per
2654 userid gracefully).
2655 FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE
2658 (since v6.3.22): If this environment variable is set and not
2659 empty, fetchmail will disable a countermeasure against an SSL
2660 CBC IV attack (by setting SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS).
2661 This is a security risk, but may be necessary for connecting to
2662 certain non-standards-conforming servers. See fetchmail's NEWS
2663 file and fetchmail-SA-2012-01.txt for details. Earlier fetch‐
2664 mail versions (v6.3.21 and older) used to disable this counter‐
2665 measure, but v6.3.22 no longer does that as a safety precaution.
2666 FETCHMAIL_POP3_FORCE_RETR
2669 (since v6.3.9): If this environment variable is defined at all
2670 (even if empty), fetchmail will forgo the POP3 TOP command and
2671 always use RETR. This can be used as a workaround when TOP does
2672 not work properly.
2673 FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS
2676 (since v6.3.17): If this environment variable is set and not
2677 empty, fetchmail will always load the default X.509 trusted cer‐
2678 tificate locations for SSL/TLS CA certificates, even if
2679 --sslcertfile and --sslcertpath are given. The latter locations
2680 take precedence over the system default locations. This is use‐
2681 ful in case there are broken certificates in the system directo‐
2682 ries and the user has no administrator privileges to remedy the
2683 problem.
2684 HOME (documented since 6.4.1): This variable is nomally set to the
2687 user's home directory. If it is set to a different directory
2688 than what is the password database, HOME takes prececence.
2689 HOME_ETC
2692 (documented corrected to match behaviour code since 6.4.1): If
2693 the HOME_ETC variable is set, it will override fetchmail's idea
2694 of $HOME, i. e. fetchmail will read .fetchmailrc, .fetchids,
2695 .fetchmail.pid and .netrc from $HOME_ETC instead of $HOME (or if
2696 HOME is also unset, from the passwd file's home directory loca‐
2697 tion).
2698 If HOME_ETC and FETCHMAILHOME are both set, FETCHMAILHOME takes
2700 prececence and HOME_ETC will be ignored.
2701 SOCKS_CONF
2704 (only if SOCKS support is compiled in) this variable is used by
2705 the socks library to find out which configuration file it should
2706 read. Set this to /dev/null to bypass the SOCKS proxy.
2707
2710 If a fetchmail daemon is running as root, SIGUSR1 wakes it up from its
2711 sleep phase and forces a poll of all non-skipped servers. For compati‐
2712 bility reasons, SIGHUP can also be used in 6.3.X but may not be avail‐
2713 able in future fetchmail versions.
2714 If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake
2716 it (this is so SIGHUP due to logout can retain the default action of
2717 killing it).
2718 Running fetchmail in foreground while a background fetchmail is running
2720 will do whichever of these is appropriate to wake it up.
2721
2724 Please check the NEWS file that shipped with fetchmail for more known
2725 bugs than those listed here.
2726 Fetchmail cannot handle user names that contain blanks after a "@"
2728 character, for instance "demonstr@ti on". These are rather uncommon and
2729 only hurt when using UID-based --keep setups, so the 6.3.X versions of
2730 fetchmail won't be fixed.
2731 Fetchmail cannot handle configurations where you have multiple accounts
2733 that use the same server name and the same login. Any user@server com‐
2734 bination must be unique.
2735 The assumptions that the DNS and in particular the checkalias options
2737 make are not often sustainable. For instance, it has become uncommon
2738 for an MX server to be a POP3 or IMAP server at the same time. There‐
2739 fore the MX lookups may go away in a future release.
2740 The mda and plugin options interact badly. In order to collect error
2742 status from the MDA, fetchmail has to change its normal signal handling
2743 so that dead plugin processes don't get reaped until the end of the
2744 poll cycle. This can cause resource starvation if too many zombies
2745 accumulate. So either don't deliver to a MDA using plugins or risk
2746 being overrun by an army of undead.
2747 The --interface option does not support IPv6 and it is doubtful if it
2749 ever will, since there is no portable way to query interface IPv6
2750 addresses.
2751 The RFC822 address parser used in multidrop mode chokes on some
2753 @-addresses that are technically legal but bizarre. Strange uses of
2754 quoting and embedded comments are likely to confuse it.
2755 In a message with multiple envelope headers, only the last one pro‐
2757 cessed will be visible to fetchmail.
2758 Use of some of these protocols requires that the program send unen‐
2760 crypted passwords over the TCP/IP connection to the mailserver. This
2761 creates a risk that name/password pairs might be snaffled with a packet
2762 sniffer or more sophisticated monitoring software. Under Linux and
2763 FreeBSD, the --interface option can be used to restrict polling to
2764 availability of a specific interface device with a specific local or
2765 remote IP address, but snooping is still possible if (a) either host
2766 has a network device that can be opened in promiscuous mode, or (b) the
2767 intervening network link can be tapped. We recommend the use of ssh(1)
2768 tunnelling to not only shroud your passwords but encrypt the entire
2769 conversation.
2770 Use of the %F or %T escapes in an mda option could open a security
2772 hole, because they pass text manipulable by an attacker to a shell com‐
2773 mand. Potential shell characters are replaced by '_' before execution.
2774 The hole is further reduced by the fact that fetchmail temporarily dis‐
2775 cards any suid privileges it may have while running the MDA. For maxi‐
2776 mum safety, however, don't use an mda command containing %F or %T when
2777 fetchmail is run from the root account itself.
2778 Fetchmail's method of sending bounces due to errors or spam-blocking
2780 and spam bounces requires that port 25 of localhost be available for
2781 sending mail via SMTP.
2782 If you modify ~/.fetchmailrc while a background instance is running and
2784 break the syntax, the background instance will die silently. Unfortu‐
2785 nately, it can't die noisily because we don't yet know whether syslog
2786 should be enabled. On some systems, fetchmail dies quietly even if
2787 there is no syntax error; this seems to have something to do with buggy
2788 terminal ioctl code in the kernel.
2789 The -f - option (reading a configuration from stdin) is incompatible
2791 with the plugin option.
2792 The 'principal' option only handles Kerberos IV, not V.
2794 Interactively entered passwords are truncated after 63 characters. If
2796 you really need to use a longer password, you will have to use a con‐
2797 figuration file.
2798 A backslash as the last character of a configuration file will be
2800 flagged as a syntax error rather than ignored.
2801 The BSMTP error handling is virtually nonexistent and may leave broken
2803 messages behind.
2804 Send comments, bug reports, gripes, and the like to the fetchmail-devel
2806 list ⟨fetchmail-devel@lists.sourceforge.net⟩
2807 An HTML FAQ ⟨http://fetchmail.sourceforge.net/fetchmail-FAQ.html⟩ is
2810 available at the fetchmail home page, it should also accompany your
2811 installation.
2812
2815 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2816 major assistance from Sunil Shetye (for code) and Rob MacGregor (for
2817 the mailing lists).
2818 Most of the code is from Eric S. Raymond ⟨esr@snark.thyrsus.com⟩ . Too
2820 many other people to name here have contributed code and patches.
2821 This program is descended from and replaces popclient, by Carl Harris
2823 ⟨ceharris@mal.com⟩ ; the internals have become quite different, but
2824 some of its interface design is directly traceable to that ancestral
2825 program.
2826 This manual page has been improved by Matthias Andree, R. Hannes Bein‐
2828 ert, and Héctor García.
2829
2832 README, README.SSL, README.SSL-SERVER, The Fetchmail FAQ ⟨http://
2833 www.fetchmail.info/fetchmail-FAQ.html⟩, mutt(1), elm(1), mail(1), send‐
2834 mail(8), popd(8), imapd(8), netrc(5).
2835 The fetchmail home page. ⟨http://www.fetchmail.info/⟩
2838 The fetchmail home page (alternative URI). ⟨http://
2841 fetchmail.sourceforge.net/⟩
2842 The maildrop home page. ⟨http://www.courier-mta.org/maildrop/⟩
2845
2848 Note that this list is just a collection of references and not a state‐
2849 ment as to the actual protocol conformance or requirements in fetch‐
2850 mail.
2851 SMTP/ESMTP:
2853 RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC
2854 1985, RFC 2554.
2855 mail:
2857 RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
2858 POP2:
2860 RFC 937
2861 POP3:
2863 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC
2864 1957, RFC 2195, RFC 2449.
2865 APOP:
2867 RFC 1939.
2868 RPOP:
2870 RFC 1081, RFC 1225.
2871 IMAP2/IMAP2BIS:
2873 RFC 1176, RFC 1732.
2874 IMAP4/IMAP4rev1:
2876 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC
2877 2177, RFC 2683.
2878 ETRN:
2880 RFC 1985.
2881 ODMR/ATRN:
2883 RFC 2645.
2884 OTP: RFC 1938.
2886 LMTP:
2888 RFC 2033.
2889 GSSAPI:
2891 RFC 1508, RFC 1734, Generic Security Service Application Program
2892 Interface (GSSAPI)/Kerberos/Simple Authentication and Security
2893 Layer (SASL) Service Names ⟨http://www.iana.org/assignments/
2894 gssapi-service-names/⟩.
2895 TLS: RFC 2595.
2897fetchmail fetchmail 6.4.1 fetchmail(1)