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.berlios.de/
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 don't specify any servers on the command
140 line, each 'poll' entry in your ~/.fetchmailrc file will be queried.
141 To facilitate the use of fetchmail in scripts and pipelines, it returns
143 an appropriate exit code upon termination -- see EXIT CODES below.
144 The following options modify the behavior of fetchmail. It is seldom
146 necessary to specify any of these once you have a working .fetchmailrc
147 file set up.
148 Almost all options have a corresponding keyword which can be used to
150 declare them in a .fetchmailrc file.
151 Some special options are not covered here, but are documented instead
153 in sections on AUTHENTICATION and DAEMON MODE which follow.
154 General Options
156 -? | --help
157 Displays option help.
158 -V | --version
160 Displays the version information for your copy of fetchmail. No
161 mail fetch is performed. Instead, for each server specified,
162 all the option information that would be computed if fetchmail
163 were connecting to that server is displayed. Any non-printables
164 in passwords or other string names are shown as backslashed C-
165 like escape sequences. This option is useful for verifying that
166 your options are set the way you want them.
167 -c | --check
169 Return a status code to indicate whether there is mail waiting,
170 without actually fetching or deleting mail (see EXIT CODES
171 below). This option turns off daemon mode (in which it would be
172 useless). It doesn't play well with queries to multiple sites,
173 and doesn't work with ETRN or ODMR. It will return a false pos‐
174 itive if you leave read but undeleted mail in your server mail‐
175 box and your fetch protocol can't tell kept messages from new
176 ones. This means it will work with IMAP, not work with POP2,
177 and may occasionally flake out under POP3.
178 -s | --silent
180 Silent mode. Suppresses all progress/status messages that are
181 normally echoed to standard output during a fetch (but does not
182 suppress actual error messages). The --verbose option overrides
183 this.
184 -v | --verbose
186 Verbose mode. All control messages passed between fetchmail and
187 the mailserver are echoed to stdout. Overrides --silent. Dou‐
188 bling this option (-v -v) causes extra diagnostic information to
189 be printed.
190 --nosoftbounce
192 (since v6.3.10, Keyword: set no softbounce, since v6.3.10)
193 Hard bounce mode. All permanent delivery errors cause messages
194 to be deleted from the upstream server, see "no softbounce"
195 below.
196 --softbounce
198 (since v6.3.10, Keyword: set softbounce, since v6.3.10)
199 Soft bounce mode. All permanent delivery errors cause messages
200 to be left on the upstream server if the protocol supports that.
201 This option is on by default to match historic fetchmail docu‐
202 mentation, and will be changed to hard bounce mode in the next
203 fetchmail release.
204 Disposal Options
206 -a | --all | (since v6.3.3) --fetchall
207 (Keyword: fetchall, since v3.0)
208 Retrieve both old (seen) and new messages from the mailserver.
209 The default is to fetch only messages the server has not marked
210 seen. Under POP3, this option also forces the use of RETR
211 rather than TOP. Note that POP2 retrieval behaves as though
212 --all is always on (see RETRIEVAL FAILURE MODES below) and this
213 option does not work with ETRN or ODMR. While the -a and --all
214 command-line and fetchall rcfile options have been supported for
215 a long time, the --fetchall command-line option was added in
216 v6.3.3.
217 -k | --keep
219 (Keyword: keep)
220 Keep retrieved messages on the remote mailserver. Normally,
221 messages are deleted from the folder on the mailserver after
222 they have been retrieved. Specifying the keep option causes
223 retrieved messages to remain in your folder on the mailserver.
224 This option does not work with ETRN or ODMR. If used with POP3,
225 it is recommended to also specify the --uidl option or uidl key‐
226 word.
227 -K | --nokeep
229 (Keyword: nokeep)
230 Delete retrieved messages from the remote mailserver. This
231 option forces retrieved mail to be deleted. It may be useful if
232 you have specified a default of keep in your .fetchmailrc. This
233 option is forced on with ETRN and ODMR.
234 -F | --flush
236 (Keyword: flush)
237 POP3/IMAP only. This is a dangerous option and can cause mail
238 loss when used improperly. It deletes old (seen) messages from
239 the mailserver before retrieving new messages. Warning: This
240 can cause mail loss if you check your mail with other clients
241 than fetchmail, and cause fetchmail to delete a message it had
242 never fetched before. It can also cause mail loss if the mail
243 server marks the message seen after retrieval (IMAP2 servers).
244 You should probably not use this option in your configuration
245 file. If you use it with POP3, you must use the 'uidl' option.
246 What you probably want is the default setting: if you don't
247 specify '-k', then fetchmail will automatically delete messages
248 after successful delivery.
249 --limitflush
251 POP3/IMAP only, since version 6.3.0. Delete oversized messages
252 from the mailserver before retrieving new messages. The size
253 limit should be separately specified with the --limit option.
254 This option does not work with ETRN or ODMR.
255 Protocol and Query Options
257 -p <proto> | --proto <proto> | --protocol <proto>
258 (Keyword: proto[col])
259 Specify the protocol to use when communicating with the remote
260 mailserver. If no protocol is specified, the default is AUTO.
261 proto may be one of the following:
262 AUTO Tries IMAP, POP3, and POP2 (skipping any of these for
264 which support has not been compiled in).
265 POP2 Post Office Protocol 2 (legacy, to be removed from future
267 release)
268 POP3 Post Office Protocol 3
270 APOP Use POP3 with old-fashioned MD5-challenge authentication.
272 Considered not resistant to man-in-the-middle attacks.
273 RPOP Use POP3 with RPOP authentication.
275 KPOP Use POP3 with Kerberos V4 authentication on port 1109.
277 SDPS Use POP3 with Demon Internet's SDPS extensions.
279 IMAP IMAP2bis, IMAP4, or IMAP4rev1 (fetchmail automatically
281 detects their capabilities).
282 ETRN Use the ESMTP ETRN option.
284 ODMR Use the the On-Demand Mail Relay ESMTP profile.
286 All these alternatives work in basically the same way (communicating
288 with standard server daemons to fetch mail already delivered to a mail‐
289 box on the server) except ETRN and ODMR. The ETRN mode allows you to
290 ask a compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
291 higher) to immediately open a sender-SMTP connection to your client
292 machine and begin forwarding any items addressed to your client machine
293 in the server's queue of undelivered mail. The ODMR mode requires an
294 ODMR-capable server and works similarly to ETRN, except that it does
295 not require the client machine to have a static DNS.
296 -U | --uidl
298 (Keyword: uidl)
299 Force UIDL use (effective only with POP3). Force client-side
300 tracking of 'newness' of messages (UIDL stands for "unique ID
301 listing" and is described in RFC1939). Use with 'keep' to use a
302 mailbox as a baby news drop for a group of users. The fact that
303 seen messages are skipped is logged, unless error logging is
304 done through syslog while running in daemon mode. Note that
305 fetchmail may automatically enable this option depending on
306 upstream server capabilities. Note also that this option may be
307 removed and forced enabled in a future fetchmail version. See
308 also: --idfile.
309 --idle (since 6.3.3)
311 (Keyword: idle, since before 6.0.0)
312 Enable IDLE use (effective only with IMAP). Note that this works
313 with only one folder at a given time. While the idle rcfile
314 keyword had been supported for a long time, the --idle command-
315 line option was added in version 6.3.3. IDLE use means that
316 fetchmail tells the IMAP server to send notice of new messages,
317 so they can be retrieved sooner than would be possible with reg‐
318 ular polls.
319 -P <portnumber> | --service <servicename>
321 (Keyword: service) Since version 6.3.0.
322 The service option permits you to specify a service name to con‐
323 nect to. You can specify a decimal port number here, if your
324 services database lacks the required service-port assignments.
325 See the FAQ item R12 and the --ssl documentation for details.
326 This replaces the older --port option.
327 --port <portnumber>
329 (Keyword: port)
330 Obsolete version of --service that does not take service names.
331 Note: this option may be removed from a future version.
332 --principal <principal>
334 (Keyword: principal)
335 The principal option permits you to specify a service principal
336 for mutual authentication. This is applicable to POP3 or IMAP
337 with Kerberos 4 authentication only. It does not apply to Ker‐
338 beros 5 or GSSAPI. This option may be removed in a future
339 fetchmail version.
340 -t <seconds> | --timeout <seconds>
342 (Keyword: timeout)
343 The timeout option allows you to set a server-nonresponse time‐
344 out in seconds. If a mailserver does not send a greeting mes‐
345 sage or respond to commands for the given number of seconds,
346 fetchmail will drop the connection to it. Without such a time‐
347 out fetchmail might hang until the TCP connection times out,
348 trying to fetch mail from a down host, which may be very long.
349 This would be particularly annoying for a fetchmail running in
350 the background. There is a default timeout which fetchmail -V
351 will report. If a given connection receives too many timeouts
352 in succession, fetchmail will consider it wedged and stop retry‐
353 ing. The calling user will be notified by email if this hap‐
354 pens.
355 Beginning with fetchmail 6.3.10, the SMTP client uses the recom‐
357 mended minimum timeouts from RFC-5321 while waiting for the
358 SMTP/LMTP server it is talking to. You can raise the timeouts
359 even more, but you cannot shorten them. This is to avoid a
360 painful situation where fetchmail has been configured with a
361 short timeout (a minute or less), ships a long message (many
362 MBytes) to the local MTA, which then takes longer than timeout
363 to respond "OK", which it eventually will; that would mean the
364 mail gets delivered properly, but fetchmail cannot notice it and
365 will thus refetch this big message over and over again.
366 --plugin <command>
368 (Keyword: plugin)
369 The plugin option allows you to use an external program to
370 establish the TCP connection. This is useful if you want to use
371 ssh, or need some special firewalling setup. The program will
372 be looked up in $PATH and can optionally be passed the hostname
373 and port as arguments using "%h" and "%p" respectively (note
374 that the interpolation logic is rather primitive, and these
375 tokens must be bounded by whitespace or beginning of string or
376 end of string). Fetchmail will write to the plugin's stdin and
377 read from the plugin's stdout.
378 --plugout <command>
380 (Keyword: plugout)
381 Identical to the plugin option above, but this one is used for
382 the SMTP connections.
383 -r <name> | --folder <name>
385 (Keyword: folder[s])
386 Causes a specified non-default mail folder on the mailserver (or
387 comma-separated list of folders) to be retrieved. The syntax of
388 the folder name is server-dependent. This option is not avail‐
389 able under POP3, ETRN, or ODMR.
390 --tracepolls
392 (Keyword: tracepolls)
393 Tell fetchmail to poll trace information in the form 'polling
394 account %s' and 'folder %s' to the Received line it generates,
395 where the %s parts are replaced by the user's remote name, the
396 poll label, and the folder (mailbox) where available (the
397 Received header also normally includes the server's true name).
398 This can be used to facilitate mail filtering based on the
399 account it is being received from. The folder information is
400 written only since version 6.3.4.
401 --ssl (Keyword: ssl)
403 Causes the connection to the mail server to be encrypted via
404 SSL, by negotiating SSL directly after connecting (SSL-wrapped
405 mode). It is highly recommended to use --sslcertck to validate
406 the certificates presented by the server. Please see the
407 description of --sslproto below! More information is available
408 in the README.SSL file that ships with fetchmail.
409 Note that even if this option is omitted, fetchmail may still
411 negotiate SSL in-band for POP3 or IMAP, through the STLS or
412 STARTTLS feature. You can use the --sslproto option to modify
413 that behavior.
414 If no port is specified, the connection is attempted to the well
416 known port of the SSL version of the base protocol. This is
417 generally a different port than the port used by the base proto‐
418 col. For IMAP, this is port 143 for the clear protocol and port
419 993 for the SSL secured protocol; for POP3, it is port 110 for
420 the clear text and port 995 for the encrypted variant.
421 If your system lacks the corresponding entries from /etc/ser‐
423 vices, see the --service option and specify the numeric port
424 number as given in the previous paragraph (unless your ISP had
425 directed you to different ports, which is uncommon however).
426 --sslcert <name>
428 (Keyword: sslcert)
429 For certificate-based client authentication. Some SSL encrypted
430 servers require client side keys and certificates for authenti‐
431 cation. In most cases, this is optional. This specifies the
432 location of the public key certificate to be presented to the
433 server at the time the SSL session is established. It is not
434 required (but may be provided) if the server does not require
435 it. It may be the same file as the private key (combined key
436 and certificate file) but this is not recommended. Also see
437 --sslkey below.
438 NOTE: If you use client authentication, the user name is fetched
440 from the certificate's CommonName and overrides the name set
441 with --user.
442 --sslkey <name>
444 (Keyword: sslkey)
445 Specifies the file name of the client side private SSL key.
446 Some SSL encrypted servers require client side keys and certifi‐
447 cates for authentication. In most cases, this is optional.
448 This specifies the location of the private key used to sign
449 transactions with the server at the time the SSL session is
450 established. It is not required (but may be provided) if the
451 server does not require it. It may be the same file as the pub‐
452 lic key (combined key and certificate file) but this is not rec‐
453 ommended.
454 If a password is required to unlock the key, it will be prompted
456 for at the time just prior to establishing the session to the
457 server. This can cause some complications in daemon mode.
458 Also see --sslcert above.
460 --sslproto <value>
462 (Keyword: sslproto)
463 This option has a dual use, out of historic fetchmail behaviour.
464 It controls both the SSL/TLS protocol version and, if --ssl is
465 not specified, the STARTTLS behaviour (upgrading the protocol to
466 an SSL or TLS connection in-band). Some other options may how‐
467 ever make TLS mandatory.
468 Only if this option and --ssl are both missing for a poll, there will
470 be opportunistic TLS for POP3 and IMAP, where fetchmail will attempt to
471 upgrade to TLSv1 or newer.
472 Recognized values for --sslproto are given below. You should normally
474 chose one of the auto-negotiating options, i. e. 'auto' or one of the
475 options ending in a plus (+) character. Note that depending on OpenSSL
476 library version and configuration, some options cause run-time errors
477 because the requested SSL or TLS versions are not supported by the par‐
478 ticular installed OpenSSL library.
479 '', the empty string
481 Disable STARTTLS. If --ssl is given for the same server,
482 log an error and pretend that 'auto' had been used
483 instead.
484 'auto' (default). Require TLS. Auto-negotiate TLSv1 or newer,
486 disable SSLv3 downgrade. (previous releases of fetchmail
487 have auto-negotiated all protocols that their OpenSSL
488 library supported, including the broken SSLv3).
489 'SSL23'
491 see 'auto'.
492 'SSL2' Require SSLv2 exactly. SSLv2 is broken, not supported on
494 all systems, avoid it if possible. This will make fetch‐
495 mail negotiate SSLv2 only, and is the only way to have
496 fetchmail permit SSLv2.
497 'SSL3' Require SSLv3 exactly. SSLv3 is broken, not supported on
499 all systems, avoid it if possible. This will make fetch‐
500 mail negotiate SSLv3 only, and is the only way besides
501 'SSL3+' to have fetchmail permit SSLv3.
502 'SSL3+'
504 same as 'auto', but permit SSLv3 as well. This is the
505 only way besides 'SSL3' to have fetchmail permit SSLv3.
506 'TLS1' Require TLSv1. This does not negotiate TLSv1.1 or newer,
508 and is discouraged. Replace by TLS1+ unless the latter
509 chokes your server.
510 'TLS1+'
512 See 'auto'.
513 'TLS1.1'
515 Require TLS v1.1 exactly.
516 'TLS1.1+'
518 Require TLS. Auto-negotiate TLSv1.1 or newer.
519 'TLS1.2'
521 Require TLS v1.2 exactly.
522 'TLS1.2+'
524 Require TLS. Auto-negotiate TLSv1.2 or 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)
534 Causes fetchmail to require that SSL/TLS be used and disconnect
535 if it can not successfully negotiate SSL or TLS, or if it cannot
536 successfully verify and validate the certificate and follow it
537 to a trust anchor (or trusted root certificate). The trust
538 anchors are given as a set of local trusted certificates (see
539 the sslcertfile and sslcertpath options). If the server certifi‐
540 cate cannot be obtained or is not signed by one of the trusted
541 ones (directly or indirectly), fetchmail will disconnect,
542 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 --sslcertfile <file>
552 (Keyword: sslcertfile, since v6.3.17)
553 Sets the file fetchmail uses to look up local certificates. The
554 default is empty. This can be given in addition to --sslcert‐
555 path below, and certificates specified in --sslcertfile will be
556 processed before those in --sslcertpath. The option can be used
557 in addition to --sslcertpath.
558 The file is a text file. It contains the concatenation of
560 trusted CA certificates in PEM format.
561 Note that using this option will suppress loading the default
563 SSL trusted CA certificates file unless you set the environment
564 variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
565 value.
566 --sslcertpath <directory>
568 (Keyword: sslcertpath)
569 Sets the directory fetchmail uses to look up local certificates.
570 The default is your OpenSSL default directory. The directory
571 must be hashed the way OpenSSL expects it - every time you add
572 or modify a certificate in the directory, you need to use the
573 c_rehash tool (which comes with OpenSSL in the tools/ subdirec‐
574 tory). Also, after OpenSSL upgrades, you may need to run
575 c_rehash; particularly when upgrading from 0.9.X to 1.0.0.
576 This can be given in addition to --sslcertfile above, which see
578 for precedence rules.
579 Note that using this option will suppress adding the default SSL
581 trusted CA certificates directory unless you set the environment
582 variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
583 value.
584 --sslcommonname <common name>
586 (Keyword: sslcommonname; since v6.3.9)
587 Use of this option is discouraged. Before using it, contact the
588 administrator of your upstream server and ask for a proper SSL
589 certificate to be used. If that cannot be attained, this option
590 can be used to specify the name (CommonName) that fetchmail
591 expects on the server certificate. A correctly configured
592 server will have this set to the hostname by which it is
593 reached, and by default fetchmail will expect as much. Use this
594 option when the CommonName is set to some other value, to avoid
595 the "Server CommonName mismatch" warning, and only if the
596 upstream server can't be made to use proper certificates.
597 --sslfingerprint <fingerprint>
599 (Keyword: sslfingerprint)
600 Specify the fingerprint of the server key (an MD5 hash of the
601 key) in hexadecimal notation with colons separating groups of
602 two digits. The letter hex digits must be in upper case. This is
603 the format that fetchmail uses to report the fingerprint when an
604 SSL connection is established. When this is specified, fetchmail
605 will compare the server key fingerprint with the given one, and
606 the connection will fail if they do not match, regardless of the
607 sslcertck setting. The connection will also fail if fetchmail
608 cannot obtain an SSL certificate from the server. This can be
609 used to prevent man-in-the-middle attacks, but the finger print
610 from the server needs to be obtained or verified over a secure
611 channel, and certainly not over the same Internet connection
612 that fetchmail would use.
613 Using this option will prevent printing certificate verification
615 errors as long as --sslcertck is unset.
616 To obtain the fingerprint of a certificate stored in the file
618 cert.pem, try:
619 openssl x509 -in cert.pem -noout -md5 -fingerprint
621 For details, see x509(1ssl).
623 Delivery Control Options
625 -S <hosts> | --smtphost <hosts>
626 (Keyword: smtp[host])
627 Specify a hunt list of hosts to forward mail to (one or more
628 hostnames, comma-separated). Hosts are tried in list order; the
629 first one that is up becomes the forwarding target for the cur‐
630 rent run. If this option is not specified, 'localhost' is used
631 as the default. Each hostname may have a port number following
632 the host name. The port number is separated from the host name
633 by a slash; the default port is "smtp". If you specify an abso‐
634 lute path name (beginning with a /), it will be interpreted as
635 the name of a UNIX socket accepting LMTP connections (such as is
636 supported by the Cyrus IMAP daemon) Example:
637 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
639 This option can be used with ODMR, and will make fetchmail a
641 relay between the ODMR server and SMTP or LMTP receiver.
642 --fetchdomains <hosts>
644 (Keyword: fetchdomains)
645 In ETRN or ODMR mode, this option specifies the list of domains
646 the server should ship mail for once the connection is turned
647 around. The default is the FQDN of the machine running fetch‐
648 mail.
649 -D <domain> | --smtpaddress <domain>
651 (Keyword: smtpaddress)
652 Specify the domain to be appended to addresses in RCPT TO lines
653 shipped to SMTP. When this is not specified, the name of the
654 SMTP server (as specified by --smtphost) is used for SMTP/LMTP
655 and 'localhost' is used for UNIX socket/BSMTP.
656 --smtpname <user@domain>
658 (Keyword: smtpname)
659 Specify the domain and user to be put in RCPT TO lines shipped
660 to SMTP. The default user is the current local user.
661 -Z <nnn> | --antispam <nnn[, nnn]...>
663 (Keyword: antispam)
664 Specifies the list of numeric SMTP errors that are to be inter‐
665 preted as a spam-block response from the listener. A value of
666 -1 disables this option. For the command-line option, the list
667 values should be comma-separated.
668 -m <command> | --mda <command>
670 (Keyword: mda)
671 This option lets fetchmail use a Message or Local Delivery Agent
672 (MDA or LDA) directly, rather than forward via SMTP or LMTP.
673 To avoid losing mail, use this option only with MDAs like mail‐
675 drop or MTAs like sendmail that exit with a nonzero status on
676 disk-full and other delivery errors; the nonzero status tells
677 fetchmail that delivery failed and prevents the message from
678 being deleted on the server.
679 If fetchmail is running as root, it sets its user id while
681 delivering mail through an MDA as follows: First, the FETCH‐
682 MAILUSER, LOGNAME, and USER environment variables are checked in
683 this order. The value of the first variable from his list that
684 is defined (even if it is empty!) is looked up in the system
685 user database. If none of the variables is defined, fetchmail
686 will use the real user id it was started with. If one of the
687 variables was defined, but the user stated there isn't found,
688 fetchmail continues running as root, without checking remaining
689 variables on the list. Practically, this means that if you run
690 fetchmail as root (not recommended), it is most useful to define
691 the FETCHMAILUSER environment variable to set the user that the
692 MDA should run as. Some MDAs (such as maildrop) are designed to
693 be setuid root and setuid to the recipient's user id, so you
694 don't lose functionality this way even when running fetchmail as
695 unprivileged user. Check the MDA's manual for details.
696 Some possible MDAs are "/usr/sbin/sendmail -i -f %F -- %T"
698 (Note: some several older or vendor sendmail versions mistake --
699 for an address, rather than an indicator to mark the end of the
700 option arguments), "/usr/bin/deliver" and "/usr/bin/maildrop -d
701 %T". Local delivery addresses will be inserted into the MDA
702 command wherever you place a %T; the mail message's From address
703 will be inserted where you place an %F.
704 Do NOT enclose the %F or %T string in single quotes! For both
706 %T and %F, fetchmail encloses the addresses in single quotes
707 ('), after removing any single quotes they may contain, before
708 the MDA command is passed to the shell.
709 Do NOT use an MDA invocation that dispatches on the contents of
711 To/Cc/Bcc, like "sendmail -i -t" or "qmail-inject", it will cre‐
712 ate mail loops and bring the just wrath of many postmasters down
713 upon your head. This is one of the most frequent configuration
714 errors!
715 Also, do not try to combine multidrop mode with an MDA such as
717 maildrop that can only accept one address, unless your upstream
718 stores one copy of the message per recipient and transports the
719 envelope recipient in a header; you will lose mail.
720 The well-known procmail(1) package is very hard to configure
722 properly, it has a very nasty "fall through to the next rule"
723 behavior on delivery errors (even temporary ones, such as out of
724 disk space if another user's mail daemon copies the mailbox
725 around to purge old messages), so your mail will end up in the
726 wrong mailbox sooner or later. The proper procmail configuration
727 is outside the scope of this document. Using maildrop(1) is usu‐
728 ally much easier, and many users find the filter syntax used by
729 maildrop easier to understand.
730 Finally, we strongly advise that you do not use qmail-inject.
732 The command line interface is non-standard without providing
733 benefits for typical use, and fetchmail makes no attempts to
734 accommodate qmail-inject's deviations from the standard. Some of
735 qmail-inject's command-line and environment options are actually
736 dangerous and can cause broken threads, non-detected duplicate
737 messages and forwarding loops.
738 --lmtp (Keyword: lmtp)
741 Cause delivery via LMTP (Local Mail Transfer Protocol). A ser‐
742 vice host and port must be explicitly specified on each host in
743 the smtphost hunt list (see above) if this option is selected;
744 the default port 25 will (in accordance with RFC 2033) not be
745 accepted.
746 --bsmtp <filename>
748 (Keyword: bsmtp)
749 Append fetched mail to a BSMTP file. This simply contains the
750 SMTP commands that would normally be generated by fetchmail when
751 passing mail to an SMTP listener daemon.
752 An argument of '-' causes the SMTP batch to be written to stan‐
754 dard output, which is of limited use: this only makes sense for
755 debugging, because fetchmail's regular output is interspersed on
756 the same channel, so this isn't suitable for mail delivery. This
757 special mode may be removed in a later release.
758 Note that fetchmail's reconstruction of MAIL FROM and RCPT TO
760 lines is not guaranteed correct; the caveats discussed under THE
761 USE AND ABUSE OF MULTIDROP MAILBOXES below apply. This mode has
762 precedence before --mda and SMTP/LMTP.
763 --bad-header {reject|accept}
765 (Keyword: bad-header; since v6.3.15)
766 Specify how fetchmail is supposed to treat messages with bad
767 headers, i. e. headers with bad syntax. Traditionally, fetchmail
768 has rejected such messages, but some distributors modified
769 fetchmail to accept them. You can now configure fetchmail's be‐
770 haviour per server.
771 Resource Limit Control Options
774 -l <maxbytes> | --limit <maxbytes>
775 (Keyword: limit)
776 Takes a maximum octet size argument, where 0 is the default and
777 also the special value designating "no limit". If nonzero, mes‐
778 sages larger than this size will not be fetched and will be left
779 on the server (in foreground sessions, the progress messages
780 will note that they are "oversized"). If the fetch protocol
781 permits (in particular, under IMAP or POP3 without the fetchall
782 option) the message will not be marked seen.
783 An explicit --limit of 0 overrides any limits set in your run
785 control file. This option is intended for those needing to
786 strictly control fetch time due to expensive and variable phone
787 rates.
788 Combined with --limitflush, it can be used to delete oversized
790 messages waiting on a server. In daemon mode, oversize notifi‐
791 cations are mailed to the calling user (see the --warnings
792 option). This option does not work with ETRN or ODMR.
793 -w <interval> | --warnings <interval>
795 (Keyword: warnings)
796 Takes an interval in seconds. When you call fetchmail with a
797 'limit' option in daemon mode, this controls the interval at
798 which warnings about oversized messages are mailed to the call‐
799 ing user (or the user specified by the 'postmaster' option).
800 One such notification is always mailed at the end of the the
801 first poll that the oversized message is detected. Thereafter,
802 re-notification is suppressed until after the warning interval
803 elapses (it will take place at the end of the first following
804 poll).
805 -b <count> | --batchlimit <count>
807 (Keyword: batchlimit)
808 Specify the maximum number of messages that will be shipped to
809 an SMTP listener before the connection is deliberately torn down
810 and rebuilt (defaults to 0, meaning no limit). An explicit
811 --batchlimit of 0 overrides any limits set in your run control
812 file. While sendmail(8) normally initiates delivery of a mes‐
813 sage immediately after receiving the message terminator, some
814 SMTP listeners are not so prompt. MTAs like smail(8) may wait
815 till the delivery socket is shut down to deliver. This may pro‐
816 duce annoying delays when fetchmail is processing very large
817 batches. Setting the batch limit to some nonzero size will pre‐
818 vent these delays. This option does not work with ETRN or ODMR.
819 -B <number> | --fetchlimit <number>
821 (Keyword: fetchlimit)
822 Limit the number of messages accepted from a given server in a
823 single poll. By default there is no limit. An explicit --fetch‐
824 limit of 0 overrides any limits set in your run control file.
825 This option does not work with ETRN or ODMR.
826 --fetchsizelimit <number>
828 (Keyword: fetchsizelimit)
829 Limit the number of sizes of messages accepted from a given
830 server in a single transaction. This option is useful in reduc‐
831 ing the delay in downloading the first mail when there are too
832 many mails in the mailbox. By default, the limit is 100. If
833 set to 0, sizes of all messages are downloaded at the start.
834 This option does not work with ETRN or ODMR. For POP3, the only
835 valid non-zero value is 1.
836 --fastuidl <number>
838 (Keyword: fastuidl)
839 Do a binary instead of linear search for the first unseen UID.
840 Binary search avoids downloading the UIDs of all mails. This
841 saves time (especially in daemon mode) where downloading the
842 same set of UIDs in each poll is a waste of bandwidth. The num‐
843 ber 'n' indicates how rarely a linear search should be done. In
844 daemon mode, linear search is used once followed by binary
845 searches in 'n-1' polls if 'n' is greater than 1; binary search
846 is always used if 'n' is 1; linear search is always used if 'n'
847 is 0. In non-daemon mode, binary search is used if 'n' is 1;
848 otherwise linear search is used. The default value of 'n' is 4.
849 This option works with POP3 only.
850 -e <count> | --expunge <count>
852 (Keyword: expunge)
853 Arrange for deletions to be made final after a given number of
854 messages. Under POP2 or POP3, fetchmail cannot make deletions
855 final without sending QUIT and ending the session -- with this
856 option on, fetchmail will break a long mail retrieval session
857 into multiple sub-sessions, sending QUIT after each sub-session.
858 This is a good defense against line drops on POP3 servers.
859 Under IMAP, fetchmail normally issues an EXPUNGE command after
860 each deletion in order to force the deletion to be done immedi‐
861 ately. This is safest when your connection to the server is
862 flaky and expensive, as it avoids resending duplicate mail after
863 a line hit. However, on large mailboxes the overhead of re-
864 indexing after every message can slam the server pretty hard, so
865 if your connection is reliable it is good to do expunges less
866 frequently. Also note that some servers enforce a delay of a
867 few seconds after each quit, so fetchmail may not be able to get
868 back in immediately after an expunge -- you may see "lock busy"
869 errors if this happens. If you specify this option to an integer
870 N, it tells fetchmail to only issue expunges on every Nth
871 delete. An argument of zero suppresses expunges entirely (so no
872 expunges at all will be done until the end of run). This option
873 does not work with ETRN or ODMR.
874 Authentication Options
877 -u <name> | --user <name> | --username <name>
878 (Keyword: user[name])
879 Specifies the user identification to be used when logging in to
880 the mailserver. The appropriate user identification is both
881 server and user-dependent. The default is your login name on
882 the client machine that is running fetchmail. See USER AUTHEN‐
883 TICATION below for a complete description.
884 -I <specification> | --interface <specification>
886 (Keyword: interface)
887 Require that a specific interface device be up and have a spe‐
888 cific local or remote IPv4 (IPv6 is not supported by this option
889 yet) address (or range) before polling. Frequently fetchmail is
890 used over a transient point-to-point TCP/IP link established
891 directly to a mailserver via SLIP or PPP. That is a relatively
892 secure channel. But when other TCP/IP routes to the mailserver
893 exist (e.g. when the link is connected to an alternate ISP),
894 your username and password may be vulnerable to snooping (espe‐
895 cially when daemon mode automatically polls for mail, shipping a
896 clear password over the net at predictable intervals). The
897 --interface option may be used to prevent this. When the speci‐
898 fied link is not up or is not connected to a matching IP
899 address, polling will be skipped. The format is:
900 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
902 The field before the first slash is the interface name (i.e.
904 sl0, ppp0 etc.). The field before the second slash is the
905 acceptable IP address. The field after the second slash is a
906 mask which specifies a range of IP addresses to accept. If no
907 mask is present 255.255.255.255 is assumed (i.e. an exact
908 match). This option is currently only supported under Linux and
909 FreeBSD. Please see the monitor section for below for FreeBSD
910 specific information.
911 Note that this option may be removed from a future fetchmail
913 version.
914 -M <interface> | --monitor <interface>
916 (Keyword: monitor)
917 Daemon mode can cause transient links which are automatically
918 taken down after a period of inactivity (e.g. PPP links) to
919 remain up indefinitely. This option identifies a system TCP/IP
920 interface to be monitored for activity. After each poll inter‐
921 val, if the link is up but no other activity has occurred on the
922 link, then the poll will be skipped. However, when fetchmail is
923 woken up by a signal, the monitor check is skipped and the poll
924 goes through unconditionally. This option is currently only
925 supported under Linux and FreeBSD. For the monitor and inter‐
926 face options to work for non root users under FreeBSD, the
927 fetchmail binary must be installed SGID kmem. This would be a
928 security hole, but fetchmail runs with the effective GID set to
929 that of the kmem group only when interface data is being col‐
930 lected.
931 Note that this option may be removed from a future fetchmail
933 version.
934 --auth <type>
936 (Keyword: auth[enticate])
937 This option permits you to specify an authentication type (see
938 USER AUTHENTICATION below for details). The possible values are
939 any, password, kerberos_v5, kerberos (or, for excruciating
940 exactness, kerberos_v4), gssapi, cram-md5, otp, ntlm, msn (only
941 for POP3), external (only IMAP) and ssh. When any (the default)
942 is specified, fetchmail tries first methods that don't require a
943 password (EXTERNAL, GSSAPI, KERBEROS IV, KERBEROS 5); then it
944 looks for methods that mask your password (CRAM-MD5, NTLM, X-OTP
945 - note that MSN is only supported for POP3, but not autoprobed);
946 and only if the server doesn't support any of those will it ship
947 your password en clair. Other values may be used to force vari‐
948 ous authentication methods (ssh suppresses authentication and is
949 thus useful for IMAP PREAUTH). (external suppresses authentica‐
950 tion and is thus useful for IMAP EXTERNAL). Any value other
951 than password, cram-md5, ntlm, msn or otp suppresses fetchmail's
952 normal inquiry for a password. Specify ssh when you are using
953 an end-to-end secure connection such as an ssh tunnel; specify
954 external when you use TLS with client authentication and specify
955 gssapi or kerberos_v4 if you are using a protocol variant that
956 employs GSSAPI or K4. Choosing KPOP protocol automatically
957 selects Kerberos authentication. This option does not work with
958 ETRN. GSSAPI service names are in line with RFC-2743 and IANA
959 registrations, see Generic Security Service Application Program
960 Interface (GSSAPI)/Kerberos/Simple Authentication and Security
961 Layer (SASL) Service Names ⟨http://www.iana.org/assignments/
962 gssapi-service-names/⟩.
963 Miscellaneous Options
965 -f <pathname> | --fetchmailrc <pathname>
966 Specify a non-default name for the ~/.fetchmailrc run control
967 file. The pathname argument must be either "-" (a single dash,
968 meaning to read the configuration from standard input) or a
969 filename. Unless the --version option is also on, a named file
970 argument must have permissions no more open than 0700
971 (u=rwx,g=,o=) or else be /dev/null.
972 -i <pathname> | --idfile <pathname>
974 (Keyword: idfile)
975 Specify an alternate name for the .fetchids file used to save
976 message UIDs. NOTE: since fetchmail 6.3.0, write access to the
977 directory containing the idfile is required, as fetchmail writes
978 a temporary file and renames it into the place of the real
979 idfile only if the temporary file has been written successfully.
980 This avoids the truncation of idfiles when running out of disk
981 space.
982 --pidfile <pathname>
984 (Keyword: pidfile; since fetchmail v6.3.4)
985 Override the default location of the PID file. Default: see
986 "ENVIRONMENT" below.
987 -n | --norewrite
989 (Keyword: no rewrite)
990 Normally, fetchmail edits RFC-822 address headers (To, From, Cc,
991 Bcc, and Reply-To) in fetched mail so that any mail IDs local to
992 the server are expanded to full addresses (@ and the mailserver
993 hostname are appended). This enables replies on the client to
994 get addressed correctly (otherwise your mailer might think they
995 should be addressed to local users on the client machine!).
996 This option disables the rewrite. (This option is provided to
997 pacify people who are paranoid about having an MTA edit mail
998 headers and want to know they can prevent it, but it is gener‐
999 ally not a good idea to actually turn off rewrite.) When using
1000 ETRN or ODMR, the rewrite option is ineffective.
1001 -E <line> | --envelope <line>
1003 (Keyword: envelope; Multidrop only)
1004 In the configuration file, an enhanced syntax is used:
1005 envelope [<count>] <line>
1006 This option changes the header fetchmail assumes will carry a
1008 copy of the mail's envelope address. Normally this is 'X-Enve‐
1009 lope-To'. Other typically found headers to carry envelope
1010 information are 'X-Original-To' and 'Delivered-To'. Now, since
1011 these headers are not standardized, practice varies. See the
1012 discussion of multidrop address handling below. As a special
1013 case, 'envelope "Received"' enables parsing of sendmail-style
1014 Received lines. This is the default, but discouraged because it
1015 is not fully reliable.
1016 Note that fetchmail expects the Received-line to be in a spe‐
1018 cific format: It must contain "by host for address", where host
1019 must match one of the mailserver names that fetchmail recognizes
1020 for the account in question.
1021 The optional count argument (only available in the configuration
1023 file) determines how many header lines of this kind are skipped.
1024 A count of 1 means: skip the first, take the second. A count of
1025 2 means: skip the first and second, take the third, and so on.
1026 -Q <prefix> | --qvirtual <prefix>
1028 (Keyword: qvirtual; Multidrop only)
1029 The string prefix assigned to this option will be removed from
1030 the user name found in the header specified with the envelope
1031 option (before doing multidrop name mapping or localdomain
1032 checking, if either is applicable). This option is useful if you
1033 are using fetchmail to collect the mail for an entire domain and
1034 your ISP (or your mail redirection provider) is using qmail.
1035 One of the basic features of qmail is the Delivered-To: message
1036 header. Whenever qmail delivers a message to a local mailbox it
1037 puts the username and hostname of the envelope recipient on this
1038 line. The major reason for this is to prevent mail loops. To
1039 set up qmail to batch mail for a disconnected site the ISP-mail‐
1040 host will have normally put that site in its 'Virtualhosts' con‐
1041 trol file so it will add a prefix to all mail addresses for this
1042 site. This results in mail sent to 'username@userhost.user‐
1043 dom.dom.com' having a Delivered-To: line of the form:
1044 Delivered-To: mbox-userstr-username@userhost.example.com
1046 The ISP can make the 'mbox-userstr-' prefix anything they choose
1048 but a string matching the user host name is likely. By using
1049 the option 'envelope Delivered-To:' you can make fetchmail reli‐
1050 ably identify the original envelope recipient, but you have to
1051 strip the 'mbox-userstr-' prefix to deliver to the correct user.
1052 This is what this option is for.
1053 --configdump
1055 Parse the ~/.fetchmailrc file, interpret any command-line
1056 options specified, and dump a configuration report to standard
1057 output. The configuration report is a data structure assignment
1058 in the language Python. This option is meant to be used with an
1059 interactive ~/.fetchmailrc editor like fetchmailconf, written in
1060 Python.
1061 -y | --yydebug
1063 Enables parser debugging, this option is meant to be used by
1064 developers only.
1065 Removed Options
1068 -T | --netsec
1069 Removed before version 6.3.0, the required underlying inet6_apps
1070 library had been discontinued and is no longer available.
1071
1074 All modes except ETRN require authentication of the client to the
1075 server. Normal user authentication in fetchmail is very much like the
1076 authentication mechanism of ftp(1). The correct user-id and password
1077 depend upon the underlying security system at the mailserver.
1078 If the mailserver is a Unix machine on which you have an ordinary user
1080 account, your regular login name and password are used with fetchmail.
1081 If you use the same login name on both the server and the client
1082 machines, you needn't worry about specifying a user-id with the -u
1083 option -- the default behavior is to use your login name on the client
1084 machine as the user-id on the server machine. If you use a different
1085 login name on the server machine, specify that login name with the -u
1086 option. e.g. if your login name is 'jsmith' on a machine named 'mail‐
1087 grunt', you would start fetchmail as follows:
1088 fetchmail -u jsmith mailgrunt
1090 The default behavior of fetchmail is to prompt you for your mailserver
1092 password before the connection is established. This is the safest way
1093 to use fetchmail and ensures that your password will not be compro‐
1094 mised. You may also specify your password in your ~/.fetchmailrc file.
1095 This is convenient when using fetchmail in daemon mode or with scripts.
1096 Using netrc files
1099 If you do not specify a password, and fetchmail cannot extract one from
1100 your ~/.fetchmailrc file, it will look for a ~/.netrc file in your home
1101 directory before requesting one interactively; if an entry matching the
1102 mailserver is found in that file, the password will be used. Fetchmail
1103 first looks for a match on poll name; if it finds none, it checks for a
1104 match on via name. See the ftp(1) man page for details of the syntax
1105 of the ~/.netrc file. To show a practical example, a .netrc might look
1106 like this:
1107 machine hermes.example.org
1109 login joe
1110 password topsecret
1111 You can repeat this block with different user information if you need
1113 to provide more than one password.
1114 This feature may allow you to avoid duplicating password information in
1116 more than one file.
1117 On mailservers that do not provide ordinary user accounts, your user-id
1119 and password are usually assigned by the server administrator when you
1120 apply for a mailbox on the server. Contact your server administrator
1121 if you don't know the correct user-id and password for your mailbox
1122 account.
1123
1125 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
1126 independent authentication using the .rhosts file on the mailserver
1127 side. Under this RPOP variant, a fixed per-user ID equivalent to a
1128 password was sent in clear over a link to a reserved port, with the
1129 command RPOP rather than PASS to alert the server that it should do
1130 special checking. RPOP is supported by fetchmail (you can specify
1131 'protocol RPOP' to have the program send 'RPOP' rather than 'PASS') but
1132 its use is strongly discouraged, and support will be removed from a
1133 future fetchmail version. This facility was vulnerable to spoofing and
1134 was withdrawn in RFC1460.
1135 RFC1460 introduced APOP authentication. In this variant of POP3, you
1137 register an APOP password on your server host (on some servers, the
1138 program to do this is called popauth(8)). You put the same password in
1139 your ~/.fetchmailrc file. Each time fetchmail logs in, it sends an MD5
1140 hash of your password and the server greeting time to the server, which
1141 can verify it by checking its authorization database.
1142 Note that APOP is no longer considered resistant against man-in-the-
1144 middle attacks.
1145 RETR or TOP
1147 fetchmail makes some efforts to make the server believe messages had
1148 not been retrieved, by using the TOP command with a large number of
1149 lines when possible. TOP is a command that retrieves the full header
1150 and a fetchmail-specified amount of body lines. It is optional and
1151 therefore not implemented by all servers, and some are known to imple‐
1152 ment it improperly. On many servers however, the RETR command which
1153 retrieves the full message with header and body, sets the "seen" flag
1154 (for instance, in a web interface), whereas the TOP command does not do
1155 that.
1156 fetchmail will always use the RETR command if "fetchall" is set.
1158 fetchmail will also use the RETR command if "keep" is set and "uidl" is
1159 unset. Finally, fetchmail will use the RETR command on Maillennium
1160 POP3/PROXY servers (used by Comcast) to avoid a deliberate TOP misin‐
1161 terpretation in this server that causes message corruption.
1162 In all other cases, fetchmail will use the TOP command. This implies
1164 that in "keep" setups, "uidl" must be set if "TOP" is desired.
1165 Note that this description is true for the current version of fetch‐
1167 mail, but the behavior may change in future versions. In particular,
1168 fetchmail may prefer the RETR command because the TOP command causes
1169 much grief on some servers and is only optional.
1170
1172 If your fetchmail was built with Kerberos support and you specify Ker‐
1173 beros authentication (either with --auth or the .fetchmailrc option
1174 authenticate kerberos_v4) it will try to get a Kerberos ticket from the
1175 mailserver at the start of each query. Note: if either the pollname or
1176 via name is 'hesiod', fetchmail will try to use Hesiod to look up the
1177 mailserver.
1178 If you use POP3 or IMAP with GSSAPI authentication, fetchmail will
1180 expect the server to have RFC1731- or RFC1734-conforming GSSAPI capa‐
1181 bility, and will use it. Currently this has only been tested over Ker‐
1182 beros V, so you're expected to already have a ticket-granting ticket.
1183 You may pass a username different from your principal name using the
1184 standard --user command or by the .fetchmailrc option user.
1185 If your IMAP daemon returns the PREAUTH response in its greeting line,
1187 fetchmail will notice this and skip the normal authentication step.
1188 This can be useful, e.g. if you start imapd explicitly using ssh. In
1189 this case you can declare the authentication value 'ssh' on that site
1190 entry to stop .fetchmail from asking you for a password when it starts
1191 up.
1192 If you use client authentication with TLS1 and your IMAP daemon returns
1194 the AUTH=EXTERNAL response, fetchmail will notice this and will use the
1195 authentication shortcut and will not send the passphrase. In this case
1196 you can declare the authentication value 'external'
1197 on that site to stop fetchmail from asking you for a password when it
1198 starts up.
1199 If you are using POP3, and the server issues a one-time-password chal‐
1201 lenge conforming to RFC1938, fetchmail will use your password as a pass
1202 phrase to generate the required response. This avoids sending secrets
1203 over the net unencrypted.
1204 Compuserve's RPA authentication is supported. If you compile in the
1206 support, fetchmail will try to perform an RPA pass-phrase authentica‐
1207 tion instead of sending over the password en clair if it detects "@com‐
1208 puserve.com" in the hostname.
1209 If you are using IMAP, Microsoft's NTLM authentication (used by Micro‐
1211 soft Exchange) is supported. If you compile in the support, fetchmail
1212 will try to perform an NTLM authentication (instead of sending over the
1213 password en clair) whenever the server returns AUTH=NTLM in its capa‐
1214 bility response. Specify a user option value that looks like
1215 'user@domain': the part to the left of the @ will be passed as the
1216 username and the part to the right as the NTLM domain.
1217 Secure Socket Layers (SSL) and Transport Layer Security (TLS)
1220 transport. Additionally, POP3 and IMAP retrival can also negotiate
1221 SSL/TLS by means of STARTTLS (or STLS).
1222 Note that fetchmail currently uses the OpenSSL library, which is se‐
1224 verely underdocumented, so failures may occur just because the program‐
1225 mers are not aware of OpenSSL's requirement of the day. For instance,
1226 since v6.3.16, fetchmail calls OpenSSL_add_all_algorithms(), which is
1227 necessary to support certificates using SHA256 on OpenSSL 0.9.8 -- this
1228 information is deeply hidden in the documentation and not at all obvi‐
1229 ous. Please do not hesitate to report subtle SSL failures.
1230 You can access SSL encrypted services by specifying the options start‐
1232 ing with --ssl, such as --ssl, --sslproto, --sslcertck, and others.
1233 You can also do this using the corresponding user options in the
1234 .fetchmailrc file. Some services, such as POP3 and IMAP, have differ‐
1235 ent well known ports defined for the SSL encrypted services. The
1236 encrypted ports will be selected automatically when SSL is enabled and
1237 no explicit port is specified. Also, the --sslcertck command line or
1238 sslcertck run control file option should be used to force strict cer‐
1239 tificate checking - see below.
1240 If SSL is not configured, fetchmail will usually opportunistically try
1242 to use STARTTLS. STARTTLS can be enforced by using --sslproto auto and
1243 defeated by using --sslproto ''. TLS connections use the same port as
1244 the unencrypted version of the protocol and negotiate TLS via special
1245 command. The --sslcertck command line or sslcertck run control file
1246 option should be used to force strict certificate checking - see below.
1247 --sslcertck is recommended: When connecting to an SSL or TLS encrypted
1249 server, the server presents a certificate to the client for validation.
1250 The certificate is checked to verify that the common name in the cer‐
1251 tificate matches the name of the server being contacted and that the
1252 effective and expiration dates in the certificate indicate that it is
1253 currently valid. If any of these checks fail, a warning message is
1254 printed, but the connection continues. The server certificate does not
1255 need to be signed by any specific Certifying Authority and may be a
1256 "self-signed" certificate. If the --sslcertck command line option or
1257 sslcertck run control file option is used, fetchmail will instead abort
1258 if any of these checks fail, because it must assume that there is a
1259 man-in-the-middle attack in this scenario, hence fetchmail must not
1260 expose cleartext passwords. Use of the sslcertck or --sslcertck option
1261 is therefore advised.
1262 Some SSL encrypted servers may request a client side certificate. A
1264 client side public SSL certificate and private SSL key may be speci‐
1265 fied. If requested by the server, the client certificate is sent to
1266 the server for validation. Some servers may require a valid client
1267 certificate and may refuse connections if a certificate is not provided
1268 or if the certificate is not valid. Some servers may require client
1269 side certificates be signed by a recognized Certifying Authority. The
1270 format for the key files and the certificate files is that required by
1271 the underlying SSL libraries (OpenSSL in the general case).
1272 A word of care about the use of SSL: While above mentioned setup with
1274 self-signed server certificates retrieved over the wires can protect
1275 you from a passive eavesdropper, it doesn't help against an active
1276 attacker. It's clearly an improvement over sending the passwords in
1277 clear, but you should be aware that a man-in-the-middle attack is triv‐
1278 ially possible (in particular with tools such as dsniff ⟨http://
1279 monkey.org/~dugsong/dsniff/⟩, ). Use of strict certificate checking
1280 with a certification authority recognized by server and client, or per‐
1281 haps of an SSH tunnel (see below for some examples) is preferable if
1282 you care seriously about the security of your mailbox and passwords.
1283 ESMTP AUTH
1286 fetchmail also supports authentication to the ESMTP server on the
1287 client side according to RFC 2554. You can specify a name/password
1288 pair to be used with the keywords 'esmtpname' and 'esmtppassword'; the
1289 former defaults to the username of the calling user.
1290
1293 Introducing the daemon mode
1294 In daemon mode, fetchmail puts itself into the background and runs for‐
1295 ever, querying each specified host and then sleeping for a given
1296 polling interval.
1297 Starting the daemon mode
1299 There are several ways to make fetchmail work in daemon mode. On the
1300 command line, --daemon <interval> or -d <interval> option runs fetch‐
1301 mail in daemon mode. You must specify a numeric argument which is a
1302 polling interval (time to wait after completing a whole poll cycle with
1303 the last server and before starting the next poll cycle with the first
1304 server) in seconds.
1305 Example: simply invoking
1307 fetchmail -d 900
1309 will, therefore, poll all the hosts described in your ~/.fetchmailrc
1311 file (except those explicitly excluded with the 'skip' verb) a bit less
1312 often than once every 15 minutes (exactly: 15 minutes + time that the
1313 poll takes).
1314 It is also possible to set a polling interval in your ~/.fetchmailrc
1316 file by saying 'set daemon <interval>', where <interval> is an integer
1317 number of seconds. If you do this, fetchmail will always start in dae‐
1318 mon mode unless you override it with the command-line option --daemon 0
1319 or -d0.
1320 Only one daemon process is permitted per user; in daemon mode, fetch‐
1322 mail sets up a per-user lockfile to guarantee this. (You can however
1323 cheat and set the FETCHMAILHOME environment variable to overcome this
1324 setting, but in that case, it is your responsibility to make sure you
1325 aren't polling the same server with two processes at the same time.)
1326 Awakening the background daemon
1328 Normally, calling fetchmail with a daemon in the background sends a
1329 wake-up signal to the daemon and quits without output. The background
1330 daemon then starts its next poll cycle immediately. The wake-up sig‐
1331 nal, SIGUSR1, can also be sent manually. The wake-up action also clears
1332 any 'wedged' flags indicating that connections have wedged due to
1333 failed authentication or multiple timeouts.
1334 Terminating the background daemon
1336 The option -q or --quit will kill a running daemon process instead of
1337 waking it up (if there is no such process, fetchmail will notify you).
1338 If the --quit option appears last on the command line, fetchmail will
1339 kill the running daemon process and then quit. Otherwise, fetchmail
1340 will first kill a running daemon process and then continue running with
1341 the other options.
1342 Useful options for daemon mode
1344 The -L <filename> or --logfile <filename> option (keyword: set logfile)
1345 is only effective when fetchmail is detached and in daemon mode. Note
1346 that the logfile must exist before fetchmail is run, you can use the
1347 touch(1) command with the filename as its sole argument to create it.
1348 This option allows you to redirect status messages into a specified
1349 logfile (follow the option with the logfile name). The logfile is
1350 opened for append, so previous messages aren't deleted. This is pri‐
1351 marily useful for debugging configurations. Note that fetchmail does
1352 not detect if the logfile is rotated, the logfile is only opened once
1353 when fetchmail starts. You need to restart fetchmail after rotating the
1354 logfile and before compressing it (if applicable).
1355 The --syslog option (keyword: set syslog) allows you to redirect status
1357 and error messages emitted to the syslog(3) system daemon if available.
1358 Messages are logged with an id of fetchmail, the facility LOG_MAIL, and
1359 priorities LOG_ERR, LOG_ALERT or LOG_INFO. This option is intended for
1360 logging status and error messages which indicate the status of the dae‐
1361 mon and the results while fetching mail from the server(s). Error mes‐
1362 sages for command line options and parsing the .fetchmailrc file are
1363 still written to stderr, or to the specified log file. The --nosyslog
1364 option turns off use of syslog(3), assuming it's turned on in the
1365 ~/.fetchmailrc file. This option is overridden, in certain situations,
1366 by --logfile (which see).
1367 The -N or --nodetach option suppresses backgrounding and detachment of
1369 the daemon process from its control terminal. This is useful for
1370 debugging or when fetchmail runs as the child of a supervisor process
1371 such as init(8) or Gerrit Pape's runit(8). Note that this also causes
1372 the logfile option to be ignored.
1373 Note that while running in daemon mode polling a POP2 or IMAP2bis
1375 server, transient errors (such as DNS failures or sendmail delivery
1376 refusals) may force the fetchall option on for the duration of the next
1377 polling cycle. This is a robustness feature. It means that if a mes‐
1378 sage is fetched (and thus marked seen by the mailserver) but not deliv‐
1379 ered locally due to some transient error, it will be re-fetched during
1380 the next poll cycle. (The IMAP logic doesn't delete messages until
1381 they're delivered, so this problem does not arise.)
1382 If you touch or change the ~/.fetchmailrc file while fetchmail is run‐
1384 ning in daemon mode, this will be detected at the beginning of the next
1385 poll cycle. When a changed ~/.fetchmailrc is detected, fetchmail
1386 rereads it and restarts from scratch (using exec(2); no state informa‐
1387 tion is retained in the new instance). Note that if fetchmail needs to
1388 query for passwords, of that if you break the ~/.fetchmailrc file's
1389 syntax, the new instance will softly and silently vanish away on
1390 startup.
1391
1394 The --postmaster <name> option (keyword: set postmaster) specifies the
1395 last-resort username to which multidrop mail is to be forwarded if no
1396 matching local recipient can be found. It is also used as destination
1397 of undeliverable mail if the 'bouncemail' global option is off and
1398 additionally for spam-blocked mail if the 'bouncemail' global option is
1399 off and the 'spambounce' global option is on. This option defaults to
1400 the user who invoked fetchmail. If the invoking user is root, then the
1401 default of this option is the user 'postmaster'. Setting postmaster to
1402 the empty string causes such mail as described above to be discarded -
1403 this however is usually a bad idea. See also the description of the
1404 'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.
1405 The --nobounce behaves like the "set no bouncemail" global option,
1407 which see.
1408 The --invisible option (keyword: set invisible) tries to make fetchmail
1410 invisible. Normally, fetchmail behaves like any other MTA would -- it
1411 generates a Received header into each message describing its place in
1412 the chain of transmission, and tells the MTA it forwards to that the
1413 mail came from the machine fetchmail itself is running on. If the
1414 invisible option is on, the Received header is suppressed and fetchmail
1415 tries to spoof the MTA it forwards to into thinking it came directly
1416 from the mailserver host.
1417 The --showdots option (keyword: set showdots) forces fetchmail to show
1419 progress dots even if the output goes to a file or fetchmail is not in
1420 verbose mode. Fetchmail shows the dots by default when run in --ver‐
1421 bose mode and output goes to console. This option is ignored in
1422 --silent mode.
1423 By specifying the --tracepolls option, you can ask fetchmail to add
1425 information to the Received header on the form "polling {label} account
1426 {user}", where {label} is the account label (from the specified rcfile,
1427 normally ~/.fetchmailrc) and {user} is the username which is used to
1428 log on to the mail server. This header can be used to make filtering
1429 email where no useful header information is available and you want mail
1430 from different accounts sorted into different mailboxes (this could,
1431 for example, occur if you have an account on the same server running a
1432 mailing list, and are subscribed to the list using that account). The
1433 default is not adding any such header. In .fetchmailrc, this is called
1434 'tracepolls'.
1435
1438 The protocols fetchmail uses to talk to mailservers are next to bullet‐
1439 proof. In normal operation forwarding to port 25, no message is ever
1440 deleted (or even marked for deletion) on the host until the SMTP lis‐
1441 tener on the client side has acknowledged to fetchmail that the message
1442 has been either accepted for delivery or rejected due to a spam block.
1443 When forwarding to an MDA, however, there is more possibility of error.
1445 Some MDAs are 'safe' and reliably return a nonzero status on any deliv‐
1446 ery error, even one due to temporary resource limits. The maildrop(1)
1447 program is like this; so are most programs designed as mail transport
1448 agents, such as sendmail(1), including the sendmail wrapper of Postfix
1449 and exim(1). These programs give back a reliable positive acknowledge‐
1450 ment and can be used with the mda option with no risk of mail loss.
1451 Unsafe MDAs, though, may return 0 even on delivery failure. If this
1452 happens, you will lose mail.
1453 The normal mode of fetchmail is to try to download only 'new' messages,
1455 leaving untouched (and undeleted) messages you have already read
1456 directly on the server (or fetched with a previous fetchmail --keep).
1457 But you may find that messages you've already read on the server are
1458 being fetched (and deleted) even when you don't specify --all. There
1459 are several reasons this can happen.
1460 One could be that you're using POP2. The POP2 protocol includes no
1462 representation of 'new' or 'old' state in messages, so fetchmail must
1463 treat all messages as new all the time. But POP2 is obsolete, so this
1464 is unlikely.
1465 A potential POP3 problem might be servers that insert messages in the
1467 middle of mailboxes (some VMS implementations of mail are rumored to do
1468 this). The fetchmail code assumes that new messages are appended to
1469 the end of the mailbox; when this is not true it may treat some old
1470 messages as new and vice versa. Using UIDL whilst setting fastuidl 0
1471 might fix this, otherwise, consider switching to IMAP.
1472 Yet another POP3 problem is that if they can't make tempfiles in the
1474 user's home directory, some POP3 servers will hand back an undocumented
1475 response that causes fetchmail to spuriously report "No mail".
1476 The IMAP code uses the presence or absence of the server flag \Seen to
1478 decide whether or not a message is new. This isn't the right thing to
1479 do, fetchmail should check the UIDVALIDITY and use UID, but it doesn't
1480 do that yet. Under Unix, it counts on your IMAP server to notice the
1481 BSD-style Status flags set by mail user agents and set the \Seen flag
1482 from them when appropriate. All Unix IMAP servers we know of do this,
1483 though it's not specified by the IMAP RFCs. If you ever trip over a
1484 server that doesn't, the symptom will be that messages you have already
1485 read on your host will look new to the server. In this (unlikely)
1486 case, only messages you fetched with fetchmail --keep will be both
1487 undeleted and marked old.
1488 In ETRN and ODMR modes, fetchmail does not actually retrieve messages;
1490 instead, it asks the server's SMTP listener to start a queue flush to
1491 the client via SMTP. Therefore it sends only undelivered messages.
1492
1495 Many SMTP listeners allow administrators to set up 'spam filters' that
1496 block unsolicited email from specified domains. A MAIL FROM or DATA
1497 line that triggers this feature will elicit an SMTP response which
1498 (unfortunately) varies according to the listener.
1499 Newer versions of sendmail return an error code of 571.
1501 According to RFC2821, the correct thing to return in this situation is
1503 550 "Requested action not taken: mailbox unavailable" (the draft adds
1504 "[E.g., mailbox not found, no access, or command rejected for policy
1505 reasons].").
1506 Older versions of the exim MTA return 501 "Syntax error in parameters
1508 or arguments".
1509 The postfix MTA runs 554 as an antispam response.
1511 Zmailer may reject code with a 500 response (followed by an enhanced
1513 status code that contains more information).
1514 Return codes which fetchmail treats as antispam responses and discards
1516 the message can be set with the 'antispam' option. This is one of the
1517 only three circumstance under which fetchmail ever discards mail (the
1518 others are the 552 and 553 errors described below, and the suppression
1519 of multidropped messages with a message-ID already seen).
1520 If fetchmail is fetching from an IMAP server, the antispam response
1522 will be detected and the message rejected immediately after the headers
1523 have been fetched, without reading the message body. Thus, you won't
1524 pay for downloading spam message bodies.
1525 By default, the list of antispam responses is empty.
1527 If the spambounce global option is on, mail that is spam-blocked trig‐
1529 gers an RFC1892/RFC1894 bounce message informing the originator that we
1530 do not accept mail from it. See also BUGS.
1531
1534 Besides the spam-blocking described above, fetchmail takes special
1535 actions — that may be modified by the --softbounce option — on the fol‐
1536 lowing SMTP/ESMTP error response codes
1537 452 (insufficient system storage)
1539 Leave the message in the server mailbox for later retrieval.
1540 552 (message exceeds fixed maximum message size)
1542 Delete the message from the server. Send bounce-mail to the orig‐
1543 inator.
1544 553 (invalid sending domain)
1546 Delete the message from the server. Don't even try to send
1547 bounce-mail to the originator.
1548 Other errors greater or equal to 500 trigger bounce mail back to the
1550 originator, unless suppressed by --softbounce. See also BUGS.
1551
1554 The preferred way to set up fetchmail is to write a .fetchmailrc file
1555 in your home directory (you may do this directly, with a text editor,
1556 or indirectly via fetchmailconf). When there is a conflict between the
1557 command-line arguments and the arguments in this file, the command-line
1558 arguments take precedence.
1559 To protect the security of your passwords, your ~/.fetchmailrc may not
1561 normally have more than 0700 (u=rwx,g=,o=) permissions; fetchmail will
1562 complain and exit otherwise (this check is suppressed when --version is
1563 on).
1564 You may read the .fetchmailrc file as a list of commands to be executed
1566 when fetchmail is called with no arguments.
1567 Run Control Syntax
1569 Comments begin with a '#' and extend through the end of the line. Oth‐
1570 erwise the file consists of a series of server entries or global option
1571 statements in a free-format, token-oriented syntax.
1572 There are four kinds of tokens: grammar keywords, numbers (i.e. decimal
1574 digit sequences), unquoted strings, and quoted strings. A quoted
1575 string is bounded by double quotes and may contain whitespace (and
1576 quoted digits are treated as a string). Note that quoted strings will
1577 also contain line feed characters if they run across two or more lines,
1578 unless you use a backslash to join lines (see below). An unquoted
1579 string is any whitespace-delimited token that is neither numeric,
1580 string quoted nor contains the special characters ',', ';', ':', or
1581 '='.
1582 Any amount of whitespace separates tokens in server entries, but is
1584 otherwise ignored. You may use backslash escape sequences (\n for LF,
1585 \t for HT, \b for BS, \r for CR, \nnn for decimal (where nnn cannot
1586 start with a 0), \0ooo for octal, and \xhh for hex) to embed non-print‐
1587 able characters or string delimiters in strings. In quoted strings, a
1588 backslash at the very end of a line will cause the backslash itself and
1589 the line feed (LF or NL, new line) character to be ignored, so that you
1590 can wrap long strings. Without the backslash at the line end, the line
1591 feed character would become part of the string.
1592 Warning: while these resemble C-style escape sequences, they are not
1594 the same. fetchmail only supports these eight styles. C supports more
1595 escape sequences that consist of backslash (\) and a single character,
1596 but does not support decimal codes and does not require the leading 0
1597 in octal notation. Example: fetchmail interprets \233 the same as \xE9
1598 (Latin small letter e with acute), where C would interpret \233 as
1599 octal 0233 = \x9B (CSI, control sequence introducer).
1600 Each server entry consists of one of the keywords 'poll' or 'skip',
1602 followed by a server name, followed by server options, followed by any
1603 number of user (or username) descriptions, followed by user options.
1604 Note: the most common cause of syntax errors is mixing up user and
1605 server options or putting user options before the user descriptions.
1606 For backward compatibility, the word 'server' is a synonym for 'poll'.
1608 You can use the noise keywords 'and', 'with', 'has', 'wants', and
1610 'options' anywhere in an entry to make it resemble English. They're
1611 ignored, but but can make entries much easier to read at a glance. The
1612 punctuation characters ':', ';' and ',' are also ignored.
1613 Poll vs. Skip
1615 The 'poll' verb tells fetchmail to query this host when it is run with
1616 no arguments. The 'skip' verb tells fetchmail not to poll this host
1617 unless it is explicitly named on the command line. (The 'skip' verb
1618 allows you to experiment with test entries safely, or easily disable
1619 entries for hosts that are temporarily down.)
1620 Keyword/Option Summary
1622 Here are the legal options. Keyword suffixes enclosed in square brack‐
1623 ets are optional. Those corresponding to short command-line options
1624 are followed by '-' and the appropriate option letter. If option is
1625 only relevant to a single mode of operation, it is noted as 's' or 'm'
1626 for singledrop- or multidrop-mode, respectively.
1627 Here are the legal global options:
1629 Keyword Opt Mode Function
1632 ────────────────────────────────────────────────────────────────────
1633 set daemon -d Set a background poll interval in
1634 seconds.
1635 set postmaster Give the name of the last-resort
1638 mail recipient (default: user run‐
1639 ning fetchmail, "postmaster" if
1640 run by the root user)
1641 set bouncemail Direct error mail to the sender
1642 (default)
1643 set no bouncemail Direct error mail to the local
1644 postmaster (as per the 'postmas‐
1645 ter' global option above).
1646 set no spambounce Do not bounce spam-blocked mail
1647 (default).
1648 set spambounce Bounce blocked spam-blocked mail
1649 (as per the 'antispam' user
1650 option) back to the destination as
1651 indicated by the 'bouncemail'
1652 global option. Warning: Do not
1653 use this to bounce spam back to
1654 the sender - most spam is sent
1655 with false sender address and thus
1656 this option hurts innocent
1657 bystanders.
1658 set no softbounce Delete permanently undeliverable
1659 mail. It is recommended to use
1660 this option if the configuration
1661 has been thoroughly tested.
1662 set softbounce Keep permanently undeliverable
1663 mail as though a temporary error
1664 had occurred (default).
1665 set logfile -L Name of a file to append error and
1666 status messages to. Only effec‐
1667 tive in daemon mode and if fetch‐
1668 mail detaches. If effective,
1669 overrides set syslog.
1670 set idfile -i Name of the file to store UID
1671 lists in.
1672 set syslog Do error logging through sys‐
1673 log(3). May be overriden by set
1674 logfile.
1675 set no syslog Turn off error logging through
1676 syslog(3). (default)
1677 set properties String value that is ignored by
1678 fetchmail (may be used by exten‐
1679 sion scripts).
1680 Here are the legal server options:
1682 Keyword Opt Mode Function
1685 ─────────────────────────────────────────────────────────────────
1686 via Specify DNS name of mailserver,
1687 overriding poll name
1688 proto[col] -p Specify protocol (case insensi‐
1689 tive): POP2, POP3, IMAP, APOP,
1690 KPOP
1691 local[domains] m Specify domain(s) to be regarded
1692 as local
1693 port Specify TCP/IP service port (obso‐
1694 lete, use 'service' instead).
1695 service -P Specify service name (a numeric
1696 value is also allowed and consid‐
1697 ered a TCP/IP port number).
1698 auth[enticate] Set authentication type (default
1699 'any')
1700 timeout -t Server inactivity timeout in sec‐
1701 onds (default 300)
1702 envelope -E m Specify envelope-address header
1703 name
1704 no envelope m Disable looking for envelope
1705 address
1706 qvirtual -Q m Qmail virtual domain prefix to
1708 remove from user name
1709 aka m Specify alternate DNS names of
1710 mailserver
1711 interface -I specify IP interface(s) that must
1712 be up for server poll to take
1713 place
1714 monitor -M Specify IP address to monitor for
1715 activity
1716 plugin Specify command through which to
1717 make server connections.
1718 plugout Specify command through which to
1719 make listener connections.
1720 dns m Enable DNS lookup for multidrop
1721 (default)
1722 no dns m Disable DNS lookup for multidrop
1723 checkalias m Do comparison by IP address for
1724 multidrop
1725 no checkalias m Do comparison by name for mul‐
1726 tidrop (default)
1727 uidl -U Force POP3 to use client-side
1728 UIDLs (recommended)
1729 no uidl Turn off POP3 use of client-side
1730 UIDLs (default)
1731 interval Only check this site every N poll
1732 cycles; N is a numeric argument.
1733 tracepolls Add poll tracing information to
1734 the Received header
1735 principal Set Kerberos principal (only use‐
1736 ful with IMAP and kerberos)
1737 esmtpname Set name for RFC2554 authentica‐
1738 tion to the ESMTP server.
1739 esmtppassword Set password for RFC2554 authenti‐
1740 cation to the ESMTP server.
1741 bad-header How to treat messages with a bad
1742 header. Can be reject (default) or
1743 accept.
1744 Here are the legal user descriptions and options:
1746 Keyword Opt Mode Function
1749 ───────────────────────────────────────────────────────────────────
1750 user[name] -u This is the user description and
1751 must come first after server
1752 description and after possible
1753 server options, and before user
1754 options.
1755 It sets the remote user name if by
1756 itself or followed by 'there', or
1757 the local user name if followed by
1758 'here'.
1759 is Connect local and remote user
1760 names
1761 to Connect local and remote user
1762 names
1763 pass[word] Specify remote account password
1764 ssl Connect to server over the speci‐
1765 fied base protocol using SSL
1766 encryption
1767 sslcert Specify file for client side pub‐
1768 lic SSL certificate
1769 sslcertfile Specify file with trusted CA cer‐
1770 tificates
1771 sslcertpath Specify c_rehash-ed directory with
1772 trusted CA certificates.
1773 sslkey Specify file for client side pri‐
1774 vate SSL key
1775 sslproto Force ssl protocol for connection
1776 folder -r Specify remote folder to query
1778 smtphost -S Specify smtp host(s) to forward to
1779 fetchdomains m Specify domains for which mail
1780 should be fetched
1781 smtpaddress -D Specify the domain to be put in
1782 RCPT TO lines
1783 smtpname Specify the user and domain to be
1784 put in RCPT TO lines
1785 antispam -Z Specify what SMTP returns are
1786 interpreted as spam-policy blocks
1787 mda -m Specify MDA for local delivery
1788 bsmtp Specify BSMTP batch file to append
1789 to
1790 preconnect Command to be executed before each
1791 connection
1792 postconnect Command to be executed after each
1793 connection
1794 keep -k Don't delete seen messages from
1795 server (for POP3, uidl is recom‐
1796 mended)
1797 flush -F Flush all seen messages before
1798 querying (DANGEROUS)
1799 limitflush Flush all oversized messages
1800 before querying
1801 fetchall -a Fetch all messages whether seen or
1802 not
1803 rewrite Rewrite destination addresses for
1804 reply (default)
1805 stripcr Strip carriage returns from ends
1806 of lines
1807 forcecr Force carriage returns at ends of
1808 lines
1809 pass8bits Force BODY=8BITMIME to ESMTP lis‐
1810 tener
1811 dropstatus Strip Status and X-Mozilla-Status
1812 lines out of incoming mail
1813 dropdelivered Strip Delivered-To lines out of
1814 incoming mail
1815 mimedecode Convert quoted-printable to 8-bit
1816 in MIME messages
1817 idle Idle waiting for new messages
1818 after each poll (IMAP only)
1819 no keep -K Delete seen messages from server
1820 (default)
1821 no flush Don't flush all seen messages
1822 before querying (default)
1823 no fetchall Retrieve only new messages
1824 (default)
1825 no rewrite Don't rewrite headers
1826 no stripcr Don't strip carriage returns
1827 (default)
1828 no forcecr Don't force carriage returns at
1829 EOL (default)
1830 no pass8bits Don't force BODY=8BITMIME to ESMTP
1831 listener (default)
1832 no dropstatus Don't drop Status headers
1833 (default)
1834 no dropdelivered Don't drop Delivered-To headers
1835 (default)
1836 no mimedecode Don't convert quoted-printable to
1837 8-bit in MIME messages (default)
1838 no idle Don't idle waiting for new mes‐
1839 sages after each poll (IMAP only)
1840 limit -l Set message size limit
1841 warnings -w Set message size warning interval
1842 batchlimit -b Max # messages to forward in sin‐
1843 gle connect
1844 fetchlimit -B Max # messages to fetch in single
1845 connect
1846 fetchsizelimit Max # message sizes to fetch in
1848 single transaction
1849 fastuidl Use binary search for first unseen
1850 message (POP3 only)
1851 expunge -e Perform an expunge on every #th
1852 message (IMAP and POP3 only)
1853 properties String value is ignored by fetch‐
1854 mail (may be used by extension
1855 scripts)
1856 All user options must begin with a user description (user or username
1858 option) and follow all server descriptions and options.
1859 In the .fetchmailrc file, the 'envelope' string argument may be pre‐
1861 ceded by a whitespace-separated number. This number, if specified, is
1862 the number of such headers to skip over (that is, an argument of 1
1863 selects the second header of the given type). This is sometime useful
1864 for ignoring bogus envelope headers created by an ISP's local delivery
1865 agent or internal forwards (through mail inspection systems, for
1866 instance).
1867 Keywords Not Corresponding To Option Switches
1869 The 'folder' and 'smtphost' options (unlike their command-line equiva‐
1870 lents) can take a space- or comma-separated list of names following
1871 them.
1872 All options correspond to the obvious command-line arguments, except
1874 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1875 'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1876 'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1877 'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus', 'dropdeliv‐
1878 ered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle', and 'no
1879 envelope'.
1880 The 'via' option is for if you want to have more than one configuration
1882 pointing at the same site. If it is present, the string argument will
1883 be taken as the actual DNS name of the mailserver host to query. This
1884 will override the argument of poll, which can then simply be a distinct
1885 label for the configuration (e.g. what you would give on the command
1886 line to explicitly query this host).
1887 The 'interval' option (which takes a numeric argument) allows you to
1889 poll a server less frequently than the basic poll interval. If you say
1890 'interval N' the server this option is attached to will only be queried
1891 every N poll intervals.
1892 Singledrop vs. Multidrop options
1894 Please ensure you read the section titled THE USE AND ABUSE OF MUL‐
1895 TIDROP MAILBOXES if you intend to use multidrop mode.
1896 The 'is' or 'to' keywords associate the following local (client)
1898 name(s) (or server-name to client-name mappings separated by =) with
1899 the mailserver user name in the entry. If an is/to list has '*' as its
1900 last name, unrecognized names are simply passed through. Note that
1901 until fetchmail version 6.3.4 inclusively, these lists could only con‐
1902 tain local parts of user names (fetchmail would only look at the part
1903 before the @ sign). fetchmail versions 6.3.5 and newer support full
1904 addresses on the left hand side of these mappings, and they take prece‐
1905 dence over any 'localdomains', 'aka', 'via' or similar mappings.
1906 A single local name can be used to support redirecting your mail when
1908 your username on the client machine is different from your name on the
1909 mailserver. When there is only a single local name, mail is forwarded
1910 to that local username regardless of the message's Received, To, Cc,
1911 and Bcc headers. In this case, fetchmail never does DNS lookups.
1912 When there is more than one local name (or name mapping), fetchmail
1914 looks at the envelope header, if configured, and otherwise at the
1915 Received, To, Cc, and Bcc headers of retrieved mail (this is 'multidrop
1916 mode'). It looks for addresses with hostname parts that match your
1917 poll name or your 'via', 'aka' or 'localdomains' options, and usually
1918 also for hostname parts which DNS tells it are aliases of the
1919 mailserver. See the discussion of 'dns', 'checkalias', 'localdomains',
1920 and 'aka' for details on how matching addresses are handled.
1921 If fetchmail cannot match any mailserver usernames or localdomain
1923 addresses, the mail will be bounced. Normally it will be bounced to
1924 the sender, but if the 'bouncemail' global option is off, the mail will
1925 go to the local postmaster instead. (see the 'postmaster' global
1926 option). See also BUGS.
1927 The 'dns' option (normally on) controls the way addresses from mul‐
1929 tidrop mailboxes are checked. On, it enables logic to check each host
1930 address that does not match an 'aka' or 'localdomains' declaration by
1931 looking it up with DNS. When a mailserver username is recognized
1932 attached to a matching hostname part, its local mapping is added to the
1933 list of local recipients.
1934 The 'checkalias' option (normally off) extends the lookups performed by
1936 the 'dns' keyword in multidrop mode, providing a way to cope with
1937 remote MTAs that identify themselves using their canonical name, while
1938 they're polled using an alias. When such a server is polled, checks to
1939 extract the envelope address fail, and fetchmail reverts to delivery
1940 using the To/Cc/Bcc headers (See below 'Header vs. Envelope
1941 addresses'). Specifying this option instructs fetchmail to retrieve
1942 all the IP addresses associated with both the poll name and the name
1943 used by the remote MTA and to do a comparison of the IP addresses.
1944 This comes in handy in situations where the remote server undergoes
1945 frequent canonical name changes, that would otherwise require modifica‐
1946 tions to the rcfile. 'checkalias' has no effect if 'no dns' is speci‐
1947 fied in the rcfile.
1948 The 'aka' option is for use with multidrop mailboxes. It allows you to
1950 pre-declare a list of DNS aliases for a server. This is an optimiza‐
1951 tion hack that allows you to trade space for speed. When fetchmail,
1952 while processing a multidrop mailbox, grovels through message headers
1953 looking for names of the mailserver, pre-declaring common ones can save
1954 it from having to do DNS lookups. Note: the names you give as argu‐
1955 ments to 'aka' are matched as suffixes -- if you specify (say) 'aka
1956 netaxs.com', this will match not just a hostname netaxs.com, but any
1957 hostname that ends with '.netaxs.com'; such as (say) pop3.netaxs.com
1958 and mail.netaxs.com.
1959 The 'localdomains' option allows you to declare a list of domains which
1961 fetchmail should consider local. When fetchmail is parsing address
1962 lines in multidrop modes, and a trailing segment of a host name matches
1963 a declared local domain, that address is passed through to the listener
1964 or MDA unaltered (local-name mappings are not applied).
1965 If you are using 'localdomains', you may also need to specify 'no enve‐
1967 lope', which disables fetchmail's normal attempt to deduce an envelope
1968 address from the Received line or X-Envelope-To header or whatever
1969 header has been previously set by 'envelope'. If you set 'no envelope'
1970 in the defaults entry it is possible to undo that in individual entries
1971 by using 'envelope <string>'. As a special case, 'envelope "Received"'
1972 restores the default parsing of Received lines.
1973 The password option requires a string argument, which is the password
1975 to be used with the entry's server.
1976 The 'preconnect' keyword allows you to specify a shell command to be
1978 executed just before each time fetchmail establishes a mailserver con‐
1979 nection. This may be useful if you are attempting to set up secure POP
1980 connections with the aid of ssh(1). If the command returns a nonzero
1981 status, the poll of that mailserver will be aborted.
1982 Similarly, the 'postconnect' keyword similarly allows you to specify a
1984 shell command to be executed just after each time a mailserver connec‐
1985 tion is taken down.
1986 The 'forcecr' option controls whether lines terminated by LF only are
1988 given CRLF termination before forwarding. Strictly speaking RFC821
1989 requires this, but few MTAs enforce the requirement it so this option
1990 is normally off (only one such MTA, qmail, is in significant use at
1991 time of writing).
1992 The 'stripcr' option controls whether carriage returns are stripped out
1994 of retrieved mail before it is forwarded. It is normally not necessary
1995 to set this, because it defaults to 'on' (CR stripping enabled) when
1996 there is an MDA declared but 'off' (CR stripping disabled) when for‐
1997 warding is via SMTP. If 'stripcr' and 'forcecr' are both on, 'stripcr'
1998 will override.
1999 The 'pass8bits' option exists to cope with Microsoft mail programs that
2001 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
2002 this option off (the default) and such a header present, fetchmail
2003 declares BODY=7BIT to an ESMTP-capable listener; this causes problems
2004 for messages actually using 8-bit ISO or KOI-8 character sets, which
2005 will be garbled by having the high bits of all characters stripped. If
2006 'pass8bits' is on, fetchmail is forced to declare BODY=8BITMIME to any
2007 ESMTP-capable listener. If the listener is 8-bit-clean (as all the
2008 major ones now are) the right thing will probably result.
2009 The 'dropstatus' option controls whether nonempty Status and X-Mozilla-
2011 Status lines are retained in fetched mail (the default) or discarded.
2012 Retaining them allows your MUA to see what messages (if any) were
2013 marked seen on the server. On the other hand, it can confuse some new-
2014 mail notifiers, which assume that anything with a Status line in it has
2015 been seen. (Note: the empty Status lines inserted by some buggy POP
2016 servers are unconditionally discarded.)
2017 The 'dropdelivered' option controls whether Delivered-To headers will
2019 be kept in fetched mail (the default) or discarded. These headers are
2020 added by Qmail and Postfix mailservers in order to avoid mail loops but
2021 may get in your way if you try to "mirror" a mailserver within the same
2022 domain. Use with caution.
2023 The 'mimedecode' option controls whether MIME messages using the
2025 quoted-printable encoding are automatically converted into pure 8-bit
2026 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean lis‐
2027 tener (that includes all of the major MTAs like sendmail), then this
2028 will automatically convert quoted-printable message headers and data
2029 into 8-bit data, making it easier to understand when reading mail. If
2030 your e-mail programs know how to deal with MIME messages, then this
2031 option is not needed. The mimedecode option is off by default, because
2032 doing RFC2047 conversion on headers throws away character-set informa‐
2033 tion and can lead to bad results if the encoding of the headers differs
2034 from the body encoding.
2035 The 'idle' option is intended to be used with IMAP servers supporting
2037 the RFC2177 IDLE command extension, but does not strictly require it.
2038 If it is enabled, and fetchmail detects that IDLE is supported, an IDLE
2039 will be issued at the end of each poll. This will tell the IMAP server
2040 to hold the connection open and notify the client when new mail is
2041 available. If IDLE is not supported, fetchmail will simulate it by
2042 periodically issuing NOOP. If you need to poll a link frequently, IDLE
2043 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
2044 sequences. On the other hand, an IDLE connection will eat almost all of
2045 your fetchmail's time, because it will never drop the connection and
2046 allow other polls to occur unless the server times out the IDLE. It
2047 also doesn't work with multiple folders; only the first folder will
2048 ever be polled.
2049 The 'properties' option is an extension mechanism. It takes a string
2052 argument, which is ignored by fetchmail itself. The string argument
2053 may be used to store configuration information for scripts which
2054 require it. In particular, the output of '--configdump' option will
2055 make properties associated with a user entry readily available to a
2056 Python script.
2057 Miscellaneous Run Control Options
2059 The words 'here' and 'there' have useful English-like significance.
2060 Normally 'user eric is esr' would mean that mail for the remote user
2061 'eric' is to be delivered to 'esr', but you can make this clearer by
2062 saying 'user eric there is esr here', or reverse it by saying 'user esr
2063 here is eric there'
2064 Legal protocol identifiers for use with the 'protocol' keyword are:
2066 auto (or AUTO) (legacy, to be removed from future release)
2068 pop2 (or POP2) (legacy, to be removed from future release)
2069 pop3 (or POP3)
2070 sdps (or SDPS)
2071 imap (or IMAP)
2072 apop (or APOP)
2073 kpop (or KPOP)
2074 Legal authentication types are 'any', 'password', 'kerberos', 'ker‐
2077 beros_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn' (only
2078 for POP3), 'ntlm', 'ssh', 'external' (only IMAP). The 'password' type
2079 specifies authentication by normal transmission of a password (the
2080 password may be plain text or subject to protocol-specific encryption
2081 as in CRAM-MD5); 'kerberos' tells fetchmail to try to get a Kerberos
2082 ticket at the start of each query instead, and send an arbitrary string
2083 as the password; and 'gssapi' tells fetchmail to use GSSAPI authentica‐
2084 tion. See the description of the 'auth' keyword for more.
2085 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
2087 authentication. These defaults may be overridden by later options.
2088 There are some global option statements: 'set logfile' followed by a
2090 string sets the same global specified by --logfile. A command-line
2091 --logfile option will override this. Note that --logfile is only effec‐
2092 tive if fetchmail detaches itself from the terminal and the logfile
2093 already exists before fetchmail is run, and it overrides --syslog in
2094 this case. Also, 'set daemon' sets the poll interval as --daemon does.
2095 This can be overridden by a command-line --daemon option; in particular
2096 --daemon 0 can be used to force foreground operation. The 'set postmas‐
2097 ter' statement sets the address to which multidrop mail defaults if
2098 there are no local matches. Finally, 'set syslog' sends log messages
2099 to syslogd(8).
2100
2103 Fetchmail crashing
2104 There are various ways in that fetchmail may "crash", i. e. stop opera‐
2105 tion suddenly and unexpectedly. A "crash" usually refers to an error
2106 condition that the software did not handle by itself. A well-known
2107 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
2108 just "segfault" for short. These can be caused by hardware or by soft‐
2109 ware problems. Software-induced segfaults can usually be reproduced
2110 easily and in the same place, whereas hardware-induced segfaults can go
2111 away if the computer is rebooted, or powered off for a few hours, and
2112 can happen in random locations even if you use the software the same
2113 way.
2114 For solving hardware-induced segfaults, find the faulty component and
2116 repair or replace it. The Sig11 FAQ ⟨http://www.bitwizard.nl/sig11/⟩
2117 may help you with details.
2118 For solving software-induced segfaults, the developers may need a
2120 "stack backtrace".
2121 Enabling fetchmail core dumps
2124 By default, fetchmail suppresses core dumps as these might contain
2125 passwords and other sensitive information. For debugging fetchmail
2126 crashes, obtaining a "stack backtrace" from a core dump is often the
2127 quickest way to solve the problem, and when posting your problem on a
2128 mailing list, the developers may ask you for a "backtrace".
2129 1. To get useful backtraces, fetchmail needs to be installed without
2131 getting stripped of its compilation symbols. Unfortunately, most
2132 binary packages that are installed are stripped, and core files from
2133 symbol-stripped programs are worthless. So you may need to recompile
2134 fetchmail. On many systems, you can type
2135 file `which fetchmail`
2137 to find out if fetchmail was symbol-stripped or not. If yours was
2139 unstripped, fine, proceed, if it was stripped, you need to recompile
2140 the source code first. You do not usually need to install fetchmail in
2141 order to debug it.
2142 2. The shell environment that starts fetchmail needs to enable core
2144 dumps. The key is the "maximum core (file) size" that can usually be
2145 configured with a tool named "limit" or "ulimit". See the documentation
2146 for your shell for details. In the popular bash shell, "ulimit -Sc
2147 unlimited" will allow the core dump.
2148 3. You need to tell fetchmail, too, to allow core dumps. To do this,
2150 run fetchmail with the -d0 -v options. It is often easier to also add
2151 --nosyslog -N as well.
2152 Finally, you need to reproduce the crash. You can just start fetchmail
2154 from the directory where you compiled it by typing ./fetchmail, so the
2155 complete command line will start with ./fetchmail -Nvd0 --nosyslog and
2156 perhaps list your other options.
2157 After the crash, run your debugger to obtain the core dump. The debug‐
2159 ger will often be GNU GDB, you can then type (adjust paths as neces‐
2160 sary) gdb ./fetchmail fetchmail.core and then, after GDB has started up
2161 and read all its files, type backtrace full, save the output (copy &
2162 paste will do, the backtrace will be read by a human) and then type
2163 quit to leave gdb. Note: on some systems, the core files have differ‐
2164 ent names, they might contain a number instead of the program name, or
2165 number and name, but it will usually have "core" as part of their name.
2166
2169 When trying to determine the originating address of a message, fetch‐
2170 mail looks through headers in the following order:
2171 Return-Path:
2173 Resent-Sender: (ignored if it doesn't contain an @ or !)
2174 Sender: (ignored if it doesn't contain an @ or !)
2175 Resent-From:
2176 From:
2177 Reply-To:
2178 Apparently-From:
2179 The originating address is used for logging, and to set the MAIL FROM
2181 address when forwarding to SMTP. This order is intended to cope grace‐
2182 fully with receiving mailing list messages in multidrop mode. The
2183 intent is that if a local address doesn't exist, the bounce message
2184 won't be returned blindly to the author or to the list itself, but
2185 rather to the list manager (which is less annoying).
2186 In multidrop mode, destination headers are processed as follows: First,
2188 fetchmail looks for the header specified by the 'envelope' option in
2189 order to determine the local recipient address. If the mail is
2190 addressed to more than one recipient, the Received line won't contain
2191 any information regarding recipient addresses.
2192 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2194 lines. If they exist, they should contain the final recipients and
2195 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
2196 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2197 looked for. (The presence of a Resent-To: is taken to imply that the
2198 person referred by the To: address has already received the original
2199 copy of the mail.)
2200
2203 Note that although there are password declarations in a good many of
2204 the examples below, this is mainly for illustrative purposes. We rec‐
2205 ommend stashing account/password pairs in your $HOME/.netrc file, where
2206 they can be used not just by fetchmail but by ftp(1) and other pro‐
2207 grams.
2208 The basic format is:
2210 poll SERVERNAME protocol PROTOCOL username NAME password PASS‐
2213 WORD
2214 Example:
2217 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2220 Or, using some abbreviations:
2223 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2226 Multiple servers may be listed:
2229 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2232 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2233 Here's the same version with more whitespace and some noise words:
2236 poll pop.provider.net proto pop3
2239 user "jsmith", with password secret1, is "jsmith" here;
2240 poll other.provider.net proto pop2:
2241 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2242 If you need to include whitespace in a parameter string or start the
2245 latter with a number, enclose the string in double quotes. Thus:
2246 poll mail.provider.net with proto pop3:
2249 user "jsmith" there has password "4u but u can't krak this"
2250 is jws here and wants mda "/bin/mail"
2251 You may have an initial server description headed by the keyword
2254 'defaults' instead of 'poll' followed by a name. Such a record is
2255 interpreted as defaults for all queries to use. It may be overwritten
2256 by individual server descriptions. So, you could write:
2257 defaults proto pop3
2260 user "jsmith"
2261 poll pop.provider.net
2262 pass "secret1"
2263 poll mail.provider.net
2264 user "jjsmith" there has password "secret2"
2265 It's possible to specify more than one user per server. The 'user'
2268 keyword leads off a user description, and every user specification in a
2269 multi-user entry must include it. Here's an example:
2270 poll pop.provider.net proto pop3 port 3111
2273 user "jsmith" with pass "secret1" is "smith" here
2274 user jones with pass "secret2" is "jjones" here keep
2275 This associates the local username 'smith' with the pop.provider.net
2278 username 'jsmith' and the local username 'jjones' with the
2279 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2280 server after download.
2281 Here's what a simple retrieval configuration for a multidrop mailbox
2284 looks like:
2285 poll pop.provider.net:
2288 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2289 This says that the mailbox of account 'maildrop' on the server is a
2292 multidrop box, and that messages in it should be parsed for the server
2293 user names 'golux', 'hurkle', and 'snark'. It further specifies that
2294 'golux' and 'snark' have the same name on the client as on the server,
2295 but mail for server user 'hurkle' should be delivered to client user
2296 'happy'.
2297 Note that fetchmail, until version 6.3.4, did NOT allow full
2300 user@domain specifications here, these would never match. Fetchmail
2301 6.3.5 and newer support user@domain specifications on the left-hand
2302 side of a user mapping.
2303 Here's an example of another kind of multidrop connection:
2306 poll pop.provider.net localdomains loonytoons.org toons.org
2309 envelope X-Envelope-To
2310 user maildrop with pass secret1 to * here
2311 This also says that the mailbox of account 'maildrop' on the server is
2314 a multidrop box. It tells fetchmail that any address in the loony‐
2315 toons.org or toons.org domains (including sub-domain addresses like
2316 'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2317 listener without modification. Be careful of mail loops if you do
2318 this!
2319 Here's an example configuration using ssh and the plugin option. The
2322 queries are made directly on the stdin and stdout of imapd via ssh.
2323 Note that in this setup, IMAP authentication can be skipped.
2324 poll mailhost.net with proto imap:
2327 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2328 user esr is esr here
2329
2332 Use the multiple-local-recipients feature with caution -- it can bite.
2333 All multidrop features are ineffective in ETRN and ODMR modes.
2334 Also, note that in multidrop mode duplicate mails are suppressed. A
2336 piece of mail is considered duplicate if it has the same message-ID as
2337 the message immediately preceding and more than one addressee. Such
2338 runs of messages may be generated when copies of a message addressed to
2339 multiple users are delivered to a multidrop box.
2340 Header vs. Envelope addresses
2343 The fundamental problem is that by having your mailserver toss several
2344 peoples' mail in a single maildrop box, you may have thrown away poten‐
2345 tially vital information about who each piece of mail was actually
2346 addressed to (the 'envelope address', as opposed to the header
2347 addresses in the RFC822 To/Cc headers - the Bcc is not available at the
2348 receiving end). This 'envelope address' is the address you need in
2349 order to reroute mail properly.
2350 Sometimes fetchmail can deduce the envelope address. If the mailserver
2352 MTA is sendmail and the item of mail had just one recipient, the MTA
2353 will have written a 'by/for' clause that gives the envelope addressee
2354 into its Received header. But this doesn't work reliably for other
2355 MTAs, nor if there is more than one recipient. By default, fetchmail
2356 looks for envelope addresses in these lines; you can restore this
2357 default with -E "Received" or 'envelope Received'.
2358 As a better alternative, some SMTP listeners and/or mail servers insert
2360 a header in each message containing a copy of the envelope addresses.
2361 This header (when it exists) is often 'X-Original-To', 'Delivered-To'
2362 or 'X-Envelope-To'. Fetchmail's assumption about this can be changed
2363 with the -E or 'envelope' option. Note that writing an envelope header
2364 of this kind exposes the names of recipients (including blind-copy
2365 recipients) to all receivers of the messages, so the upstream must
2366 store one copy of the message per recipient to avoid becoming a privacy
2367 problem.
2368 Postfix, since version 2.0, writes an X-Original-To: header which con‐
2370 tains a copy of the envelope as it was received.
2371 Qmail and Postfix generally write a 'Delivered-To' header upon deliver‐
2373 ing the message to the mail spool and use it to avoid mail loops.
2374 Qmail virtual domains however will prefix the user name with a string
2375 that normally matches the user's domain. To remove this prefix you can
2376 use the -Q or 'qvirtual' option.
2377 Sometimes, unfortunately, neither of these methods works. That is the
2379 point when you should contact your ISP and ask them to provide such an
2380 envelope header, and you should not use multidrop in this situation.
2381 When they all fail, fetchmail must fall back on the contents of To/Cc
2382 headers (Bcc headers are not available - see below) to try to determine
2383 recipient addressees -- and these are unreliable. In particular, mail‐
2384 ing-list software often ships mail with only the list broadcast address
2385 in the To header.
2386 Note that a future version of fetchmail may remove To/Cc parsing!
2388 When fetchmail cannot deduce a recipient address that is local, and the
2390 intended recipient address was anyone other than fetchmail's invoking
2391 user, mail will get lost. This is what makes the multidrop feature
2392 risky without proper envelope information.
2393 A related problem is that when you blind-copy a mail message, the Bcc
2395 information is carried only as envelope address (it's removed from the
2396 headers by the sending mail server, so fetchmail can see it only if
2397 there is an X-Envelope-To header). Thus, blind-copying to someone who
2398 gets mail over a fetchmail multidrop link will fail unless the the
2399 mailserver host routinely writes X-Envelope-To or an equivalent header
2400 into messages in your maildrop.
2401 In conclusion, mailing lists and Bcc'd mail can only work if the server
2403 you're fetching from
2404 (1) stores one copy of the message per recipient in your domain and
2406 (2) records the envelope information in a special header (X-Origi‐
2408 nal-To, Delivered-To, X-Envelope-To).
2409 Good Ways To Use Multidrop Mailboxes
2412 Multiple local names can be used to administer a mailing list from the
2413 client side of a fetchmail collection. Suppose your name is 'esr', and
2414 you want to both pick up your own mail and maintain a mailing list
2415 called (say) "fetchmail-friends", and you want to keep the alias list
2416 on your client machine.
2417 On your server, you can alias 'fetchmail-friends' to 'esr'; then, in
2419 your .fetchmailrc, declare 'to esr fetchmail-friends here'. Then, when
2420 mail including 'fetchmail-friends' as a local address gets fetched, the
2421 list name will be appended to the list of recipients your SMTP listener
2422 sees. Therefore it will undergo alias expansion locally. Be sure to
2423 include 'esr' in the local alias expansion of fetchmail-friends, or
2424 you'll never see mail sent only to the list. Also be sure that your
2425 listener has the "me-too" option set (sendmail's -oXm command-line
2426 option or OXm declaration) so your name isn't removed from alias expan‐
2427 sions in messages you send.
2428 This trick is not without its problems, however. You'll begin to see
2430 this when a message comes in that is addressed only to a mailing list
2431 you do not have declared as a local name. Each such message will fea‐
2432 ture an 'X-Fetchmail-Warning' header which is generated because fetch‐
2433 mail cannot find a valid local name in the recipient addresses. Such
2434 messages default (as was described above) to being sent to the local
2435 user running fetchmail, but the program has no way to know that that's
2436 actually the right thing.
2437 Bad Ways To Abuse Multidrop Mailboxes
2440 Multidrop mailboxes and fetchmail serving multiple users in daemon mode
2441 do not mix. The problem, again, is mail from mailing lists, which typ‐
2442 ically does not have an individual recipient address on it. Unless
2443 fetchmail can deduce an envelope address, such mail will only go to the
2444 account running fetchmail (probably root). Also, blind-copied users
2445 are very likely never to see their mail at all.
2446 If you're tempted to use fetchmail to retrieve mail for multiple users
2448 from a single mail drop via POP or IMAP, think again (and reread the
2449 section on header and envelope addresses above). It would be smarter
2450 to just let the mail sit in the mailserver's queue and use fetchmail's
2451 ETRN or ODMR modes to trigger SMTP sends periodically (of course, this
2452 means you have to poll more frequently than the mailserver's expiry
2453 period). If you can't arrange this, try setting up a UUCP feed.
2454 If you absolutely must use multidrop for this purpose, make sure your
2456 mailserver writes an envelope-address header that fetchmail can see.
2457 Otherwise you will lose mail and it will come back to haunt you.
2458 Speeding Up Multidrop Checking
2461 Normally, when multiple users are declared fetchmail extracts recipient
2462 addresses as described above and checks each host part with DNS to see
2463 if it's an alias of the mailserver. If so, the name mappings described
2464 in the "to ... here" declaration are done and the mail locally deliv‐
2465 ered.
2466 This is a convenient but also slow method. To speed it up, pre-declare
2468 mailserver aliases with 'aka'; these are checked before DNS lookups are
2469 done. If you're certain your aka list contains all DNS aliases of the
2470 mailserver (and all MX names pointing at it - note this may change in a
2471 future version) you can declare 'no dns' to suppress DNS lookups
2472 entirely and only match against the aka list.
2473
2476 Support for socks4/5 is a compile time configuration option. Once com‐
2477 piled in, fetchmail will always use the socks libraries and configura‐
2478 tion on your system, there are no run-time switches in fetchmail - but
2479 you can still configure SOCKS: you can specify which SOCKS configura‐
2480 tion file is used in the SOCKS_CONF environment variable.
2481 For instance, if you wanted to bypass the SOCKS proxy altogether and
2483 have fetchmail connect directly, you could just pass
2484 SOCKS_CONF=/dev/null in the environment, for example (add your usual
2485 command line options - if any - to the end of this line):
2486 env SOCKS_CONF=/dev/null fetchmail
2488
2491 To facilitate the use of fetchmail in shell scripts, an exit status
2492 code is returned to give an indication of what occurred during a given
2493 connection.
2494 The exit codes returned by fetchmail are as follows:
2496 0 One or more messages were successfully retrieved (or, if the -c
2498 option was selected, were found waiting but not retrieved).
2499 1 There was no mail awaiting retrieval. (There may have been old
2501 mail still on the server but not selected for retrieval.) If you
2502 do not want "no mail" to be an error condition (for instance,
2503 for cron jobs), use a POSIX-compliant shell and add
2504 || [ $? -eq 1 ]
2506 to the end of the fetchmail command line, note that this leaves
2508 0 untouched, maps 1 to 0, and maps all other codes to 1. See
2509 also item #C8 in the FAQ.
2510 2 An error was encountered when attempting to open a socket to
2512 retrieve mail. If you don't know what a socket is, don't worry
2513 about it -- just treat this as an 'unrecoverable error'. This
2514 error can also be because a protocol fetchmail wants to use is
2515 not listed in /etc/services.
2516 3 The user authentication step failed. This usually means that a
2518 bad user-id, password, or APOP id was specified. Or it may mean
2519 that you tried to run fetchmail under circumstances where it did
2520 not have standard input attached to a terminal and could not
2521 prompt for a missing password.
2522 4 Some sort of fatal protocol error was detected.
2524 5 There was a syntax error in the arguments to fetchmail, or a
2526 pre- or post-connect command failed.
2527 6 The run control file had bad permissions.
2529 7 There was an error condition reported by the server. Can also
2531 fire if fetchmail timed out while waiting for the server.
2532 8 Client-side exclusion error. This means fetchmail either found
2534 another copy of itself already running, or failed in such a way
2535 that it isn't sure whether another copy is running.
2536 9 The user authentication step failed because the server responded
2538 "lock busy". Try again after a brief pause! This error is not
2539 implemented for all protocols, nor for all servers. If not
2540 implemented for your server, "3" will be returned instead, see
2541 above. May be returned when talking to qpopper or other servers
2542 that can respond with "lock busy" or some similar text contain‐
2543 ing the word "lock".
2544 10 The fetchmail run failed while trying to do an SMTP port open or
2546 transaction.
2547 11 Fatal DNS error. Fetchmail encountered an error while perform‐
2549 ing a DNS lookup at startup and could not proceed.
2550 12 BSMTP batch file could not be opened.
2552 13 Poll terminated by a fetch limit (see the --fetchlimit option).
2554 14 Server busy indication.
2556 23 Internal error. You should see a message on standard error with
2558 details.
2559 24 - 26, 28, 29
2561 These are internal codes and should not appear externally.
2562 When fetchmail queries more than one host, return status is 0 if any
2564 query successfully retrieved mail. Otherwise the returned error status
2565 is that of the last host queried.
2566
2569 ~/.fetchmailrc
2570 default run control file
2571 ~/.fetchids
2573 default location of file recording last message UIDs seen per
2574 host.
2575 ~/.fetchmail.pid
2577 lock file to help prevent concurrent runs (non-root mode).
2578 ~/.netrc
2580 your FTP run control file, which (if present) will be searched for
2581 passwords as a last resort before prompting for one interactively.
2582 /var/run/fetchmail.pid
2584 lock file to help prevent concurrent runs (root mode, Linux sys‐
2585 tems).
2586 /etc/fetchmail.pid
2588 lock file to help prevent concurrent runs (root mode, systems
2589 without /var/run).
2590
2593 FETCHMAILHOME
2594 If this environment variable is set to a valid and existing
2595 directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
2596 (the dot is missing in this case), $FETCHMAILHOME/.fetchids and
2597 $FETCHMAILHOME/.fetchmail.pid rather than from the user's home
2598 directory. The .netrc file is always looked for in the the
2599 invoking user's home directory regardless of FETCHMAILHOME's
2600 setting.
2601 FETCHMAILUSER
2604 If this environment variable is set, it is used as the name of
2605 the calling user (default local name) for purposes such as mail‐
2606 ing error notifications. Otherwise, if either the LOGNAME or
2607 USER variable is correctly set (e.g. the corresponding UID
2608 matches the session user ID) then that name is used as the
2609 default local name. Otherwise getpwuid(3) must be able to
2610 retrieve a password entry for the session ID (this elaborate
2611 logic is designed to handle the case of multiple names per
2612 userid gracefully).
2613 FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE
2616 (since v6.3.22): If this environment variable is set and not
2617 empty, fetchmail will disable a countermeasure against an SSL
2618 CBC IV attack (by setting SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS).
2619 This is a security risk, but may be necessary for connecting to
2620 certain non-standards-conforming servers. See fetchmail's NEWS
2621 file and fetchmail-SA-2012-01.txt for details. Earlier fetch‐
2622 mail versions (v6.3.21 and older) used to disable this counter‐
2623 measure, but v6.3.22 no longer does that as a safety precaution.
2624 FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS
2627 (since v6.3.17): If this environment variable is set and not
2628 empty, fetchmail will always load the default X.509 trusted cer‐
2629 tificate locations for SSL/TLS CA certificates, even if
2630 --sslcertfile and --sslcertpath are given. The latter locations
2631 take precedence over the system default locations. This is use‐
2632 ful in case there are broken certificates in the system directo‐
2633 ries and the user has no administrator privileges to remedy the
2634 problem.
2635 HOME_ETC
2638 If the HOME_ETC variable is set, fetchmail will read
2639 $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.
2640 If HOME_ETC and FETCHMAILHOME are both set, HOME_ETC will be
2642 ignored.
2643 SOCKS_CONF
2646 (only if SOCKS support is compiled in) this variable is used by
2647 the socks library to find out which configuration file it should
2648 read. Set this to /dev/null to bypass the SOCKS proxy.
2649
2652 If a fetchmail daemon is running as root, SIGUSR1 wakes it up from its
2653 sleep phase and forces a poll of all non-skipped servers. For compati‐
2654 bility reasons, SIGHUP can also be used in 6.3.X but may not be avail‐
2655 able in future fetchmail versions.
2656 If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake
2658 it (this is so SIGHUP due to logout can retain the default action of
2659 killing it).
2660 Running fetchmail in foreground while a background fetchmail is running
2662 will do whichever of these is appropriate to wake it up.
2663
2666 Please check the NEWS file that shipped with fetchmail for more known
2667 bugs than those listed here.
2668 Fetchmail cannot handle user names that contain blanks after a "@"
2670 character, for instance "demonstr@ti on". These are rather uncommon and
2671 only hurt when using UID-based --keep setups, so the 6.3.X versions of
2672 fetchmail won't be fixed.
2673 Fetchmail cannot handle configurations where you have multiple accounts
2675 that use the same server name and the same login. Any user@server com‐
2676 bination must be unique.
2677 The assumptions that the DNS and in particular the checkalias options
2679 make are not often sustainable. For instance, it has become uncommon
2680 for an MX server to be a POP3 or IMAP server at the same time. There‐
2681 fore the MX lookups may go away in a future release.
2682 The mda and plugin options interact badly. In order to collect error
2684 status from the MDA, fetchmail has to change its normal signal handling
2685 so that dead plugin processes don't get reaped until the end of the
2686 poll cycle. This can cause resource starvation if too many zombies
2687 accumulate. So either don't deliver to a MDA using plugins or risk
2688 being overrun by an army of undead.
2689 The --interface option does not support IPv6 and it is doubtful if it
2691 ever will, since there is no portable way to query interface IPv6
2692 addresses.
2693 The RFC822 address parser used in multidrop mode chokes on some
2695 @-addresses that are technically legal but bizarre. Strange uses of
2696 quoting and embedded comments are likely to confuse it.
2697 In a message with multiple envelope headers, only the last one pro‐
2699 cessed will be visible to fetchmail.
2700 Use of some of these protocols requires that the program send unen‐
2702 crypted passwords over the TCP/IP connection to the mailserver. This
2703 creates a risk that name/password pairs might be snaffled with a packet
2704 sniffer or more sophisticated monitoring software. Under Linux and
2705 FreeBSD, the --interface option can be used to restrict polling to
2706 availability of a specific interface device with a specific local or
2707 remote IP address, but snooping is still possible if (a) either host
2708 has a network device that can be opened in promiscuous mode, or (b) the
2709 intervening network link can be tapped. We recommend the use of ssh(1)
2710 tunnelling to not only shroud your passwords but encrypt the entire
2711 conversation.
2712 Use of the %F or %T escapes in an mda option could open a security
2714 hole, because they pass text manipulable by an attacker to a shell com‐
2715 mand. Potential shell characters are replaced by '_' before execution.
2716 The hole is further reduced by the fact that fetchmail temporarily dis‐
2717 cards any suid privileges it may have while running the MDA. For maxi‐
2718 mum safety, however, don't use an mda command containing %F or %T when
2719 fetchmail is run from the root account itself.
2720 Fetchmail's method of sending bounces due to errors or spam-blocking
2722 and spam bounces requires that port 25 of localhost be available for
2723 sending mail via SMTP.
2724 If you modify ~/.fetchmailrc while a background instance is running and
2726 break the syntax, the background instance will die silently. Unfortu‐
2727 nately, it can't die noisily because we don't yet know whether syslog
2728 should be enabled. On some systems, fetchmail dies quietly even if
2729 there is no syntax error; this seems to have something to do with buggy
2730 terminal ioctl code in the kernel.
2731 The -f - option (reading a configuration from stdin) is incompatible
2733 with the plugin option.
2734 The 'principal' option only handles Kerberos IV, not V.
2736 Interactively entered passwords are truncated after 63 characters. If
2738 you really need to use a longer password, you will have to use a con‐
2739 figuration file.
2740 A backslash as the last character of a configuration file will be
2742 flagged as a syntax error rather than ignored.
2743 The BSMTP error handling is virtually nonexistent and may leave broken
2745 messages behind.
2746 Send comments, bug reports, gripes, and the like to the fetchmail-devel
2748 list ⟨fetchmail-devel@lists.berlios.de⟩
2749 An HTML FAQ ⟨http://fetchmail.berlios.de/fetchmail-FAQ.html⟩ is avail‐
2752 able at the fetchmail home page, it should also accompany your instal‐
2753 lation.
2754
2757 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2758 major assistance from Sunil Shetye (for code) and Rob MacGregor (for
2759 the mailing lists).
2760 Most of the code is from Eric S. Raymond ⟨esr@snark.thyrsus.com⟩ . Too
2762 many other people to name here have contributed code and patches.
2763 This program is descended from and replaces popclient, by Carl Harris
2765 ⟨ceharris@mal.com⟩ ; the internals have become quite different, but
2766 some of its interface design is directly traceable to that ancestral
2767 program.
2768 This manual page has been improved by Matthias Andree, R. Hannes Bein‐
2770 ert, and Héctor García.
2771
2774 README, README.SSL, README.SSL-SERVER, The Fetchmail FAQ ⟨http://
2775 www.fetchmail.info/fetchmail-FAQ.html⟩, mutt(1), elm(1), mail(1), send‐
2776 mail(8), popd(8), imapd(8), netrc(5).
2777 The fetchmail home page. ⟨http://fetchmail.berlios.de/⟩
2780 The maildrop home page. ⟨http://www.courier-mta.org/maildrop/⟩
2783
2786 Note that this list is just a collection of references and not a state‐
2787 ment as to the actual protocol conformance or requirements in fetch‐
2788 mail.
2789 SMTP/ESMTP:
2791 RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC
2792 1985, RFC 2554.
2793 mail:
2795 RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
2796 POP2:
2798 RFC 937
2799 POP3:
2801 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC
2802 1957, RFC 2195, RFC 2449.
2803 APOP:
2805 RFC 1939.
2806 RPOP:
2808 RFC 1081, RFC 1225.
2809 IMAP2/IMAP2BIS:
2811 RFC 1176, RFC 1732.
2812 IMAP4/IMAP4rev1:
2814 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC
2815 2177, RFC 2683.
2816 ETRN:
2818 RFC 1985.
2819 ODMR/ATRN:
2821 RFC 2645.
2822 OTP: RFC 1938.
2824 LMTP:
2826 RFC 2033.
2827 GSSAPI:
2829 RFC 1508, RFC 1734, Generic Security Service Application Program
2830 Interface (GSSAPI)/Kerberos/Simple Authentication and Security
2831 Layer (SASL) Service Names ⟨http://www.iana.org/assignments/
2832 gssapi-service-names/⟩.
2833 TLS: RFC 2595.
2835fetchmail fetchmail 6.3.26 fetchmail(1)