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 Default to match historic fetchmail documentation, to be changed
202 to hard bounce mode in the next fetchmail release.
203 Disposal Options
205 -a | --all | (since v6.3.3) --fetchall
206 (Keyword: fetchall, since v3.0)
207 Retrieve both old (seen) and new messages from the mailserver.
208 The default is to fetch only messages the server has not marked
209 seen. Under POP3, this option also forces the use of RETR
210 rather than TOP. Note that POP2 retrieval behaves as though
211 --all is always on (see RETRIEVAL FAILURE MODES below) and this
212 option does not work with ETRN or ODMR. While the -a and --all
213 command-line and fetchall rcfile options have been supported for
214 a long time, the --fetchall command-line option was added in
215 v6.3.3.
216 -k | --keep
218 (Keyword: keep)
219 Keep retrieved messages on the remote mailserver. Normally,
220 messages are deleted from the folder on the mailserver after
221 they have been retrieved. Specifying the keep option causes
222 retrieved messages to remain in your folder on the mailserver.
223 This option does not work with ETRN or ODMR. If used with POP3,
224 it is recommended to also specify the --uidl option or uidl key‐
225 word.
226 -K | --nokeep
228 (Keyword: nokeep)
229 Delete retrieved messages from the remote mailserver. This
230 option forces retrieved mail to be deleted. It may be useful if
231 you have specified a default of keep in your .fetchmailrc. This
232 option is forced on with ETRN and ODMR.
233 -F | --flush
235 (Keyword: flush)
236 POP3/IMAP only. This is a dangerous option and can cause mail
237 loss when used improperly. It deletes old (seen) messages from
238 the mailserver before retrieving new messages. Warning: This
239 can cause mail loss if you check your mail with other clients
240 than fetchmail, and cause fetchmail to delete a message it had
241 never fetched before. It can also cause mail loss if the mail
242 server marks the message seen after retrieval (IMAP2 servers).
243 You should probably not use this option in your configuration
244 file. If you use it with POP3, you must use the 'uidl' option.
245 What you probably want is the default setting: if you don't
246 specify '-k', then fetchmail will automatically delete messages
247 after successful delivery.
248 --limitflush
250 POP3/IMAP only, since version 6.3.0. Delete oversized messages
251 from the mailserver before retrieving new messages. The size
252 limit should be separately specified with the --limit option.
253 This option does not work with ETRN or ODMR.
254 Protocol and Query Options
256 -p <proto> | --proto <proto> | --protocol <proto>
257 (Keyword: proto[col])
258 Specify the protocol to use when communicating with the remote
259 mailserver. If no protocol is specified, the default is AUTO.
260 proto may be one of the following:
261 AUTO Tries IMAP, POP3, and POP2 (skipping any of these for
263 which support has not been compiled in).
264 POP2 Post Office Protocol 2 (legacy, to be removed from future
266 release)
267 POP3 Post Office Protocol 3
269 APOP Use POP3 with old-fashioned MD5-challenge authentication.
271 Considered not resistant to man-in-the-middle attacks.
272 RPOP Use POP3 with RPOP authentication.
274 KPOP Use POP3 with Kerberos V4 authentication on port 1109.
276 SDPS Use POP3 with Demon Internet's SDPS extensions.
278 IMAP IMAP2bis, IMAP4, or IMAP4rev1 (fetchmail automatically
280 detects their capabilities).
281 ETRN Use the ESMTP ETRN option.
283 ODMR Use the the On-Demand Mail Relay ESMTP profile.
285 All these alternatives work in basically the same way (communicating
287 with standard server daemons to fetch mail already delivered to a mail‐
288 box on the server) except ETRN and ODMR. The ETRN mode allows you to
289 ask a compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
290 higher) to immediately open a sender-SMTP connection to your client
291 machine and begin forwarding any items addressed to your client machine
292 in the server's queue of undelivered mail. The ODMR mode requires an
293 ODMR-capable server and works similarly to ETRN, except that it does
294 not require the client machine to have a static DNS.
295 -U | --uidl
297 (Keyword: uidl)
298 Force UIDL use (effective only with POP3). Force client-side
299 tracking of 'newness' of messages (UIDL stands for "unique ID
300 listing" and is described in RFC1939). Use with 'keep' to use a
301 mailbox as a baby news drop for a group of users. The fact that
302 seen messages are skipped is logged, unless error logging is
303 done through syslog while running in daemon mode. Note that
304 fetchmail may automatically enable this option depending on
305 upstream server capabilities. Note also that this option may be
306 removed and forced enabled in a future fetchmail version. See
307 also: --idfile.
308 --idle (since 6.3.3)
310 (Keyword: idle, since before 6.0.0)
311 Enable IDLE use (effective only with IMAP). Note that this works
312 with only one folder at a given time. While the idle rcfile
313 keyword had been supported for a long time, the --idle command-
314 line option was added in version 6.3.3. IDLE use means that
315 fetchmail tells the IMAP server to send notice of new messages,
316 so they can be retrieved sooner than would be possible with reg‐
317 ular polls.
318 -P <portnumber> | --service <servicename>
320 (Keyword: service) Since version 6.3.0.
321 The service option permits you to specify a service name to con‐
322 nect to. You can specify a decimal port number here, if your
323 services database lacks the required service-port assignments.
324 See the FAQ item R12 and the --ssl documentation for details.
325 This replaces the older --port option.
326 --port <portnumber>
328 (Keyword: port)
329 Obsolete version of --service that does not take service names.
330 Note: this option may be removed from a future version.
331 --principal <principal>
333 (Keyword: principal)
334 The principal option permits you to specify a service principal
335 for mutual authentication. This is applicable to POP3 or IMAP
336 with Kerberos 4 authentication only. It does not apply to Ker‐
337 beros 5 or GSSAPI. This option may be removed in a future
338 fetchmail version.
339 -t <seconds> | --timeout <seconds>
341 (Keyword: timeout)
342 The timeout option allows you to set a server-nonresponse time‐
343 out in seconds. If a mailserver does not send a greeting mes‐
344 sage or respond to commands for the given number of seconds,
345 fetchmail will drop the connection to it. Without such a time‐
346 out fetchmail might hang until the TCP connection times out,
347 trying to fetch mail from a down host, which may be very long.
348 This would be particularly annoying for a fetchmail running in
349 the background. There is a default timeout which fetchmail -V
350 will report. If a given connection receives too many timeouts
351 in succession, fetchmail will consider it wedged and stop retry‐
352 ing. The calling user will be notified by email if this hap‐
353 pens.
354 Beginning with fetchmail 6.3.10, the SMTP client uses the recom‐
356 mended minimum timeouts from RFC-5321 while waiting for the
357 SMTP/LMTP server it is talking to. You can raise the timeouts
358 even more, but you cannot shorten them. This is to avoid a
359 painful situation where fetchmail has been configured with a
360 short timeout (a minute or less), ships a long message (many
361 MBytes) to the local MTA, which then takes longer than timeout
362 to respond "OK", which it eventually will; that would mean the
363 mail gets delivered properly, but fetchmail cannot notice it and
364 will thus refetch this big message over and over again.
365 --plugin <command>
367 (Keyword: plugin)
368 The plugin option allows you to use an external program to
369 establish the TCP connection. This is useful if you want to use
370 ssh, or need some special firewalling setup. The program will
371 be looked up in $PATH and can optionally be passed the hostname
372 and port as arguments using "%h" and "%p" respectively (note
373 that the interpolation logic is rather primitive, and these
374 tokens must be bounded by whitespace or beginning of string or
375 end of string). Fetchmail will write to the plugin's stdin and
376 read from the plugin's stdout.
377 --plugout <command>
379 (Keyword: plugout)
380 Identical to the plugin option above, but this one is used for
381 the SMTP connections.
382 -r <name> | --folder <name>
384 (Keyword: folder[s])
385 Causes a specified non-default mail folder on the mailserver (or
386 comma-separated list of folders) to be retrieved. The syntax of
387 the folder name is server-dependent. This option is not avail‐
388 able under POP3, ETRN, or ODMR.
389 --tracepolls
391 (Keyword: tracepolls)
392 Tell fetchmail to poll trace information in the form 'polling
393 account %s' and 'folder %s' to the Received line it generates,
394 where the %s parts are replaced by the user's remote name, the
395 poll label, and the folder (mailbox) where available (the
396 Received header also normally includes the server's true name).
397 This can be used to facilitate mail filtering based on the
398 account it is being received from. The folder information is
399 written only since version 6.3.4.
400 --ssl (Keyword: ssl)
402 Causes the connection to the mail server to be encrypted via
403 SSL, by negotiating SSL directly after connecting (SSL-wrapped
404 mode). It is highly recommended to use --sslcertck to validate
405 the certificates presented by the server. Please see the
406 description of --sslproto below! More information is available
407 in the README.SSL file that ships with fetchmail.
408 Note that even if this option is omitted, fetchmail may still
410 negotiate SSL in-band for POP3 or IMAP, through the STLS or
411 STARTTLS feature. You can use the --sslproto option to modify
412 that behavior.
413 If no port is specified, the connection is attempted to the well
415 known port of the SSL version of the base protocol. This is
416 generally a different port than the port used by the base proto‐
417 col. For IMAP, this is port 143 for the clear protocol and port
418 993 for the SSL secured protocol; for POP3, it is port 110 for
419 the clear text and port 995 for the encrypted variant.
420 If your system lacks the corresponding entries from /etc/ser‐
422 vices, see the --service option and specify the numeric port
423 number as given in the previous paragraph (unless your ISP had
424 directed you to different ports, which is uncommon however).
425 --sslcert <name>
427 (Keyword: sslcert)
428 For certificate-based client authentication. Some SSL encrypted
429 servers require client side keys and certificates for authenti‐
430 cation. In most cases, this is optional. This specifies the
431 location of the public key certificate to be presented to the
432 server at the time the SSL session is established. It is not
433 required (but may be provided) if the server does not require
434 it. It may be the same file as the private key (combined key
435 and certificate file) but this is not recommended. Also see
436 --sslkey below.
437 NOTE: If you use client authentication, the user name is fetched
439 from the certificate's CommonName and overrides the name set
440 with --user.
441 --sslkey <name>
443 (Keyword: sslkey)
444 Specifies the file name of the client side private SSL key.
445 Some SSL encrypted servers require client side keys and certifi‐
446 cates for authentication. In most cases, this is optional.
447 This specifies the location of the private key used to sign
448 transactions with the server at the time the SSL session is
449 established. It is not required (but may be provided) if the
450 server does not require it. It may be the same file as the pub‐
451 lic key (combined key and certificate file) but this is not rec‐
452 ommended.
453 If a password is required to unlock the key, it will be prompted
455 for at the time just prior to establishing the session to the
456 server. This can cause some complications in daemon mode.
457 Also see --sslcert above.
459 --sslproto <value>
461 (Keyword: sslproto)
462 This option has a dual use, out of historic fetchmail behaviour.
463 It controls both the SSL/TLS protocol version and, if --ssl is
464 not specified, the STARTTLS behaviour (upgrading the protocol to
465 an SSL or TLS connection in-band). Some other options may how‐
466 ever make TLS mandatory.
467 Only if this option and --ssl are both missing for a poll, there will
469 be opportunistic TLS for POP3 and IMAP, where fetchmail will attempt to
470 upgrade to TLSv1 or newer.
471 Recognized values for --sslproto are given below. You should normally
473 chose one of the auto-negotiating options, i. e. 'auto' or one of the
474 options ending in a plus (+) character. Note that depending on OpenSSL
475 library version and configuration, some options cause run-time errors
476 because the requested SSL or TLS versions are not supported by the par‐
477 ticular installed OpenSSL library.
478 '', the empty string
480 Disable STARTTLS. If --ssl is given for the same server,
481 log an error and pretend that 'auto' had been used
482 instead.
483 'auto' (default). Require TLS. Auto-negotiate TLSv1 or newer,
485 disable SSLv3 downgrade. (previous releases of fetchmail
486 have auto-negotiated all protocols that their OpenSSL
487 library supported, including the broken SSLv3).
488 'SSL23'
490 see 'auto'.
491 'SSL2' Require SSLv2 exactly. SSLv2 is broken, not supported on
493 all systems, avoid it if possible. This will make fetch‐
494 mail negotiate SSLv2 only, and is the only way to have
495 fetchmail permit SSLv2.
496 'SSL3' Require SSLv3 exactly. SSLv3 is broken, not supported on
498 all systems, avoid it if possible. This will make fetch‐
499 mail negotiate SSLv3 only, and is the only way besides
500 'SSL3+' to have fetchmail permit SSLv3.
501 'SSL3+'
503 same as 'auto', but permit SSLv3 as well. This is the
504 only way besides 'SSL3' to have fetchmail permit SSLv3.
505 'TLS1' Require TLSv1. This does not negotiate TLSv1.1 or newer,
507 and is discouraged. Replace by TLS1+ unless the latter
508 chokes your server.
509 'TLS1+'
511 See 'auto'.
512 'TLS1.1'
514 Require TLS v1.1 exactly.
515 'TLS1.1+'
517 Require TLS. Auto-negotiate TLSv1.1 or newer.
518 'TLS1.2'
520 Require TLS v1.2 exactly.
521 'TLS1.2+'
523 Require TLS. Auto-negotiate TLSv1.2 or newer.
524 Unrecognized parameters
526 are treated the same as 'auto'.
527 NOTE: you should hardly ever need to use anything other than ''
529 (to force an unencrypted connection) or 'auto' (to enforce TLS).
530 --sslcertck
532 (Keyword: sslcertck)
533 Causes fetchmail to require that SSL/TLS be used and disconnect
534 if it can not successfully negotiate SSL or TLS, or if it cannot
535 successfully verify and validate the certificate and follow it
536 to a trust anchor (or trusted root certificate). The trust
537 anchors are given as a set of local trusted certificates (see
538 the sslcertfile and sslcertpath options). If the server certifi‐
539 cate cannot be obtained or is not signed by one of the trusted
540 ones (directly or indirectly), fetchmail will disconnect,
541 regardless of the sslfingerprint option.
542 Note that CRL (certificate revocation lists) are only supported
544 in OpenSSL 0.9.7 and newer! Your system clock should also be
545 reasonably accurate when using this option.
546 Note that this optional behavior may become default behavior in
548 future fetchmail versions.
549 --sslcertfile <file>
551 (Keyword: sslcertfile, since v6.3.17)
552 Sets the file fetchmail uses to look up local certificates. The
553 default is empty. This can be given in addition to --sslcert‐
554 path below, and certificates specified in --sslcertfile will be
555 processed before those in --sslcertpath. The option can be used
556 in addition to --sslcertpath.
557 The file is a text file. It contains the concatenation of
559 trusted CA certificates in PEM format.
560 Note that using this option will suppress loading the default
562 SSL trusted CA certificates file unless you set the environment
563 variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
564 value.
565 --sslcertpath <directory>
567 (Keyword: sslcertpath)
568 Sets the directory fetchmail uses to look up local certificates.
569 The default is your OpenSSL default directory. The directory
570 must be hashed the way OpenSSL expects it - every time you add
571 or modify a certificate in the directory, you need to use the
572 c_rehash tool (which comes with OpenSSL in the tools/ subdirec‐
573 tory). Also, after OpenSSL upgrades, you may need to run
574 c_rehash; particularly when upgrading from 0.9.X to 1.0.0.
575 This can be given in addition to --sslcertfile above, which see
577 for precedence rules.
578 Note that using this option will suppress adding the default SSL
580 trusted CA certificates directory unless you set the environment
581 variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
582 value.
583 --sslcommonname <common name>
585 (Keyword: sslcommonname; since v6.3.9)
586 Use of this option is discouraged. Before using it, contact the
587 administrator of your upstream server and ask for a proper SSL
588 certificate to be used. If that cannot be attained, this option
589 can be used to specify the name (CommonName) that fetchmail
590 expects on the server certificate. A correctly configured
591 server will have this set to the hostname by which it is
592 reached, and by default fetchmail will expect as much. Use this
593 option when the CommonName is set to some other value, to avoid
594 the "Server CommonName mismatch" warning, and only if the
595 upstream server can't be made to use proper certificates.
596 --sslfingerprint <fingerprint>
598 (Keyword: sslfingerprint)
599 Specify the fingerprint of the server key (an MD5 hash of the
600 key) in hexadecimal notation with colons separating groups of
601 two digits. The letter hex digits must be in upper case. This is
602 the default format OpenSSL uses, and the one fetchmail uses to
603 report the fingerprint when an SSL connection is established.
604 When this is specified, fetchmail will compare the server key
605 fingerprint with the given one, and the connection will fail if
606 they do not match regardless of the sslcertck setting. The con‐
607 nection will also fail if fetchmail cannot obtain an SSL cer‐
608 tificate from the server. This can be used to prevent man-in-
609 the-middle attacks, but the finger print from the server needs
610 to be obtained or verified over a secure channel, and certainly
611 not over the same Internet connection that fetchmail would use.
612 Using this option will prevent printing certificate verification
614 errors as long as --sslcertck is unset.
615 To obtain the fingerprint of a certificate stored in the file
617 cert.pem, try:
618 openssl x509 -in cert.pem -noout -md5 -fingerprint
620 For details, see x509(1ssl).
622 Delivery Control Options
624 -S <hosts> | --smtphost <hosts>
625 (Keyword: smtp[host])
626 Specify a hunt list of hosts to forward mail to (one or more
627 hostnames, comma-separated). Hosts are tried in list order; the
628 first one that is up becomes the forwarding target for the cur‐
629 rent run. If this option is not specified, 'localhost' is used
630 as the default. Each hostname may have a port number following
631 the host name. The port number is separated from the host name
632 by a slash; the default port is "smtp". If you specify an abso‐
633 lute path name (beginning with a /), it will be interpreted as
634 the name of a UNIX socket accepting LMTP connections (such as is
635 supported by the Cyrus IMAP daemon) Example:
636 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
638 This option can be used with ODMR, and will make fetchmail a
640 relay between the ODMR server and SMTP or LMTP receiver.
641 --fetchdomains <hosts>
643 (Keyword: fetchdomains)
644 In ETRN or ODMR mode, this option specifies the list of domains
645 the server should ship mail for once the connection is turned
646 around. The default is the FQDN of the machine running fetch‐
647 mail.
648 -D <domain> | --smtpaddress <domain>
650 (Keyword: smtpaddress)
651 Specify the domain to be appended to addresses in RCPT TO lines
652 shipped to SMTP. When this is not specified, the name of the
653 SMTP server (as specified by --smtphost) is used for SMTP/LMTP
654 and 'localhost' is used for UNIX socket/BSMTP.
655 --smtpname <user@domain>
657 (Keyword: smtpname)
658 Specify the domain and user to be put in RCPT TO lines shipped
659 to SMTP. The default user is the current local user.
660 -Z <nnn> | --antispam <nnn[, nnn]...>
662 (Keyword: antispam)
663 Specifies the list of numeric SMTP errors that are to be inter‐
664 preted as a spam-block response from the listener. A value of
665 -1 disables this option. For the command-line option, the list
666 values should be comma-separated.
667 -m <command> | --mda <command>
669 (Keyword: mda)
670 This option lets fetchmail use a Message or Local Delivery Agent
671 (MDA or LDA) directly, rather than forward via SMTP or LMTP.
672 To avoid losing mail, use this option only with MDAs like mail‐
674 drop or MTAs like sendmail that exit with a nonzero status on
675 disk-full and other delivery errors; the nonzero status tells
676 fetchmail that delivery failed and prevents the message from
677 being deleted on the server.
678 If fetchmail is running as root, it sets its user id while
680 delivering mail through an MDA as follows: First, the FETCH‐
681 MAILUSER, LOGNAME, and USER environment variables are checked in
682 this order. The value of the first variable from his list that
683 is defined (even if it is empty!) is looked up in the system
684 user database. If none of the variables is defined, fetchmail
685 will use the real user id it was started with. If one of the
686 variables was defined, but the user stated there isn't found,
687 fetchmail continues running as root, without checking remaining
688 variables on the list. Practically, this means that if you run
689 fetchmail as root (not recommended), it is most useful to define
690 the FETCHMAILUSER environment variable to set the user that the
691 MDA should run as. Some MDAs (such as maildrop) are designed to
692 be setuid root and setuid to the recipient's user id, so you
693 don't lose functionality this way even when running fetchmail as
694 unprivileged user. Check the MDA's manual for details.
695 Some possible MDAs are "/usr/sbin/sendmail -i -f %F -- %T"
697 (Note: some several older or vendor sendmail versions mistake --
698 for an address, rather than an indicator to mark the end of the
699 option arguments), "/usr/bin/deliver" and "/usr/bin/maildrop -d
700 %T". Local delivery addresses will be inserted into the MDA
701 command wherever you place a %T; the mail message's From address
702 will be inserted where you place an %F.
703 Do NOT enclose the %F or %T string in single quotes! For both
705 %T and %F, fetchmail encloses the addresses in single quotes
706 ('), after removing any single quotes they may contain, before
707 the MDA command is passed to the shell.
708 Do NOT use an MDA invocation that dispatches on the contents of
710 To/Cc/Bcc, like "sendmail -i -t" or "qmail-inject", it will cre‐
711 ate mail loops and bring the just wrath of many postmasters down
712 upon your head. This is one of the most frequent configuration
713 errors!
714 Also, do not try to combine multidrop mode with an MDA such as
716 maildrop that can only accept one address, unless your upstream
717 stores one copy of the message per recipient and transports the
718 envelope recipient in a header; you will lose mail.
719 The well-known procmail(1) package is very hard to configure
721 properly, it has a very nasty "fall through to the next rule"
722 behavior on delivery errors (even temporary ones, such as out of
723 disk space if another user's mail daemon copies the mailbox
724 around to purge old messages), so your mail will end up in the
725 wrong mailbox sooner or later. The proper procmail configuration
726 is outside the scope of this document. Using maildrop(1) is usu‐
727 ally much easier, and many users find the filter syntax used by
728 maildrop easier to understand.
729 Finally, we strongly advise that you do not use qmail-inject.
731 The command line interface is non-standard without providing
732 benefits for typical use, and fetchmail makes no attempts to
733 accommodate qmail-inject's deviations from the standard. Some of
734 qmail-inject's command-line and environment options are actually
735 dangerous and can cause broken threads, non-detected duplicate
736 messages and forwarding loops.
737 --lmtp (Keyword: lmtp)
740 Cause delivery via LMTP (Local Mail Transfer Protocol). A ser‐
741 vice host and port must be explicitly specified on each host in
742 the smtphost hunt list (see above) if this option is selected;
743 the default port 25 will (in accordance with RFC 2033) not be
744 accepted.
745 --bsmtp <filename>
747 (Keyword: bsmtp)
748 Append fetched mail to a BSMTP file. This simply contains the
749 SMTP commands that would normally be generated by fetchmail when
750 passing mail to an SMTP listener daemon.
751 An argument of '-' causes the SMTP batch to be written to stan‐
753 dard output, which is of limited use: this only makes sense for
754 debugging, because fetchmail's regular output is interspersed on
755 the same channel, so this isn't suitable for mail delivery. This
756 special mode may be removed in a later release.
757 Note that fetchmail's reconstruction of MAIL FROM and RCPT TO
759 lines is not guaranteed correct; the caveats discussed under THE
760 USE AND ABUSE OF MULTIDROP MAILBOXES below apply. This mode has
761 precedence before --mda and SMTP/LMTP.
762 --bad-header {reject|accept}
764 (Keyword: bad-header; since v6.3.15)
765 Specify how fetchmail is supposed to treat messages with bad
766 headers, i. e. headers with bad syntax. Traditionally, fetchmail
767 has rejected such messages, but some distributors modified
768 fetchmail to accept them. You can now configure fetchmail's be‐
769 haviour per server.
770 Resource Limit Control Options
773 -l <maxbytes> | --limit <maxbytes>
774 (Keyword: limit)
775 Takes a maximum octet size argument, where 0 is the default and
776 also the special value designating "no limit". If nonzero, mes‐
777 sages larger than this size will not be fetched and will be left
778 on the server (in foreground sessions, the progress messages
779 will note that they are "oversized"). If the fetch protocol
780 permits (in particular, under IMAP or POP3 without the fetchall
781 option) the message will not be marked seen.
782 An explicit --limit of 0 overrides any limits set in your run
784 control file. This option is intended for those needing to
785 strictly control fetch time due to expensive and variable phone
786 rates.
787 Combined with --limitflush, it can be used to delete oversized
789 messages waiting on a server. In daemon mode, oversize notifi‐
790 cations are mailed to the calling user (see the --warnings
791 option). This option does not work with ETRN or ODMR.
792 -w <interval> | --warnings <interval>
794 (Keyword: warnings)
795 Takes an interval in seconds. When you call fetchmail with a
796 'limit' option in daemon mode, this controls the interval at
797 which warnings about oversized messages are mailed to the call‐
798 ing user (or the user specified by the 'postmaster' option).
799 One such notification is always mailed at the end of the the
800 first poll that the oversized message is detected. Thereafter,
801 re-notification is suppressed until after the warning interval
802 elapses (it will take place at the end of the first following
803 poll).
804 -b <count> | --batchlimit <count>
806 (Keyword: batchlimit)
807 Specify the maximum number of messages that will be shipped to
808 an SMTP listener before the connection is deliberately torn down
809 and rebuilt (defaults to 0, meaning no limit). An explicit
810 --batchlimit of 0 overrides any limits set in your run control
811 file. While sendmail(8) normally initiates delivery of a mes‐
812 sage immediately after receiving the message terminator, some
813 SMTP listeners are not so prompt. MTAs like smail(8) may wait
814 till the delivery socket is shut down to deliver. This may pro‐
815 duce annoying delays when fetchmail is processing very large
816 batches. Setting the batch limit to some nonzero size will pre‐
817 vent these delays. This option does not work with ETRN or ODMR.
818 -B <number> | --fetchlimit <number>
820 (Keyword: fetchlimit)
821 Limit the number of messages accepted from a given server in a
822 single poll. By default there is no limit. An explicit --fetch‐
823 limit of 0 overrides any limits set in your run control file.
824 This option does not work with ETRN or ODMR.
825 --fetchsizelimit <number>
827 (Keyword: fetchsizelimit)
828 Limit the number of sizes of messages accepted from a given
829 server in a single transaction. This option is useful in reduc‐
830 ing the delay in downloading the first mail when there are too
831 many mails in the mailbox. By default, the limit is 100. If
832 set to 0, sizes of all messages are downloaded at the start.
833 This option does not work with ETRN or ODMR. For POP3, the only
834 valid non-zero value is 1.
835 --fastuidl <number>
837 (Keyword: fastuidl)
838 Do a binary instead of linear search for the first unseen UID.
839 Binary search avoids downloading the UIDs of all mails. This
840 saves time (especially in daemon mode) where downloading the
841 same set of UIDs in each poll is a waste of bandwidth. The num‐
842 ber 'n' indicates how rarely a linear search should be done. In
843 daemon mode, linear search is used once followed by binary
844 searches in 'n-1' polls if 'n' is greater than 1; binary search
845 is always used if 'n' is 1; linear search is always used if 'n'
846 is 0. In non-daemon mode, binary search is used if 'n' is 1;
847 otherwise linear search is used. The default value of 'n' is 4.
848 This option works with POP3 only.
849 -e <count> | --expunge <count>
851 (Keyword: expunge)
852 Arrange for deletions to be made final after a given number of
853 messages. Under POP2 or POP3, fetchmail cannot make deletions
854 final without sending QUIT and ending the session -- with this
855 option on, fetchmail will break a long mail retrieval session
856 into multiple sub-sessions, sending QUIT after each sub-session.
857 This is a good defense against line drops on POP3 servers.
858 Under IMAP, fetchmail normally issues an EXPUNGE command after
859 each deletion in order to force the deletion to be done immedi‐
860 ately. This is safest when your connection to the server is
861 flaky and expensive, as it avoids resending duplicate mail after
862 a line hit. However, on large mailboxes the overhead of re-
863 indexing after every message can slam the server pretty hard, so
864 if your connection is reliable it is good to do expunges less
865 frequently. Also note that some servers enforce a delay of a
866 few seconds after each quit, so fetchmail may not be able to get
867 back in immediately after an expunge -- you may see "lock busy"
868 errors if this happens. If you specify this option to an integer
869 N, it tells fetchmail to only issue expunges on every Nth
870 delete. An argument of zero suppresses expunges entirely (so no
871 expunges at all will be done until the end of run). This option
872 does not work with ETRN or ODMR.
873 Authentication Options
876 -u <name> | --user <name> | --username <name>
877 (Keyword: user[name])
878 Specifies the user identification to be used when logging in to
879 the mailserver. The appropriate user identification is both
880 server and user-dependent. The default is your login name on
881 the client machine that is running fetchmail. See USER AUTHEN‐
882 TICATION below for a complete description.
883 -I <specification> | --interface <specification>
885 (Keyword: interface)
886 Require that a specific interface device be up and have a spe‐
887 cific local or remote IPv4 (IPv6 is not supported by this option
888 yet) address (or range) before polling. Frequently fetchmail is
889 used over a transient point-to-point TCP/IP link established
890 directly to a mailserver via SLIP or PPP. That is a relatively
891 secure channel. But when other TCP/IP routes to the mailserver
892 exist (e.g. when the link is connected to an alternate ISP),
893 your username and password may be vulnerable to snooping (espe‐
894 cially when daemon mode automatically polls for mail, shipping a
895 clear password over the net at predictable intervals). The
896 --interface option may be used to prevent this. When the speci‐
897 fied link is not up or is not connected to a matching IP
898 address, polling will be skipped. The format is:
899 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
901 The field before the first slash is the interface name (i.e.
903 sl0, ppp0 etc.). The field before the second slash is the
904 acceptable IP address. The field after the second slash is a
905 mask which specifies a range of IP addresses to accept. If no
906 mask is present 255.255.255.255 is assumed (i.e. an exact
907 match). This option is currently only supported under Linux and
908 FreeBSD. Please see the monitor section for below for FreeBSD
909 specific information.
910 Note that this option may be removed from a future fetchmail
912 version.
913 -M <interface> | --monitor <interface>
915 (Keyword: monitor)
916 Daemon mode can cause transient links which are automatically
917 taken down after a period of inactivity (e.g. PPP links) to
918 remain up indefinitely. This option identifies a system TCP/IP
919 interface to be monitored for activity. After each poll inter‐
920 val, if the link is up but no other activity has occurred on the
921 link, then the poll will be skipped. However, when fetchmail is
922 woken up by a signal, the monitor check is skipped and the poll
923 goes through unconditionally. This option is currently only
924 supported under Linux and FreeBSD. For the monitor and inter‐
925 face options to work for non root users under FreeBSD, the
926 fetchmail binary must be installed SGID kmem. This would be a
927 security hole, but fetchmail runs with the effective GID set to
928 that of the kmem group only when interface data is being col‐
929 lected.
930 Note that this option may be removed from a future fetchmail
932 version.
933 --auth <type>
935 (Keyword: auth[enticate])
936 This option permits you to specify an authentication type (see
937 USER AUTHENTICATION below for details). The possible values are
938 any, password, kerberos_v5, kerberos (or, for excruciating
939 exactness, kerberos_v4), gssapi, cram-md5, otp, ntlm, msn (only
940 for POP3), external (only IMAP) and ssh. When any (the default)
941 is specified, fetchmail tries first methods that don't require a
942 password (EXTERNAL, GSSAPI, KERBEROS IV, KERBEROS 5); then it
943 looks for methods that mask your password (CRAM-MD5, NTLM, X-OTP
944 - note that MSN is only supported for POP3, but not autoprobed);
945 and only if the server doesn't support any of those will it ship
946 your password en clair. Other values may be used to force vari‐
947 ous authentication methods (ssh suppresses authentication and is
948 thus useful for IMAP PREAUTH). (external suppresses authentica‐
949 tion and is thus useful for IMAP EXTERNAL). Any value other
950 than password, cram-md5, ntlm, msn or otp suppresses fetchmail's
951 normal inquiry for a password. Specify ssh when you are using
952 an end-to-end secure connection such as an ssh tunnel; specify
953 external when you use TLS with client authentication and specify
954 gssapi or kerberos_v4 if you are using a protocol variant that
955 employs GSSAPI or K4. Choosing KPOP protocol automatically
956 selects Kerberos authentication. This option does not work with
957 ETRN. GSSAPI service names are in line with RFC-2743 and IANA
958 registrations, see Generic Security Service Application Program
959 Interface (GSSAPI)/Kerberos/Simple Authentication and Security
960 Layer (SASL) Service Names ⟨http://www.iana.org/assignments/
961 gssapi-service-names/⟩.
962 Miscellaneous Options
964 -f <pathname> | --fetchmailrc <pathname>
965 Specify a non-default name for the ~/.fetchmailrc run control
966 file. The pathname argument must be either "-" (a single dash,
967 meaning to read the configuration from standard input) or a
968 filename. Unless the --version option is also on, a named file
969 argument must have permissions no more open than 0700
970 (u=rwx,g=,o=) or else be /dev/null.
971 -i <pathname> | --idfile <pathname>
973 (Keyword: idfile)
974 Specify an alternate name for the .fetchids file used to save
975 message UIDs. NOTE: since fetchmail 6.3.0, write access to the
976 directory containing the idfile is required, as fetchmail writes
977 a temporary file and renames it into the place of the real
978 idfile only if the temporary file has been written successfully.
979 This avoids the truncation of idfiles when running out of disk
980 space.
981 --pidfile <pathname>
983 (Keyword: pidfile; since fetchmail v6.3.4)
984 Override the default location of the PID file. Default: see
985 "ENVIRONMENT" below.
986 -n | --norewrite
988 (Keyword: no rewrite)
989 Normally, fetchmail edits RFC-822 address headers (To, From, Cc,
990 Bcc, and Reply-To) in fetched mail so that any mail IDs local to
991 the server are expanded to full addresses (@ and the mailserver
992 hostname are appended). This enables replies on the client to
993 get addressed correctly (otherwise your mailer might think they
994 should be addressed to local users on the client machine!).
995 This option disables the rewrite. (This option is provided to
996 pacify people who are paranoid about having an MTA edit mail
997 headers and want to know they can prevent it, but it is gener‐
998 ally not a good idea to actually turn off rewrite.) When using
999 ETRN or ODMR, the rewrite option is ineffective.
1000 -E <line> | --envelope <line>
1002 (Keyword: envelope; Multidrop only)
1003 In the configuration file, an enhanced syntax is used:
1004 envelope [<count>] <line>
1005 This option changes the header fetchmail assumes will carry a
1007 copy of the mail's envelope address. Normally this is 'X-Enve‐
1008 lope-To'. Other typically found headers to carry envelope
1009 information are 'X-Original-To' and 'Delivered-To'. Now, since
1010 these headers are not standardized, practice varies. See the
1011 discussion of multidrop address handling below. As a special
1012 case, 'envelope "Received"' enables parsing of sendmail-style
1013 Received lines. This is the default, but discouraged because it
1014 is not fully reliable.
1015 Note that fetchmail expects the Received-line to be in a spe‐
1017 cific format: It must contain "by host for address", where host
1018 must match one of the mailserver names that fetchmail recognizes
1019 for the account in question.
1020 The optional count argument (only available in the configuration
1022 file) determines how many header lines of this kind are skipped.
1023 A count of 1 means: skip the first, take the second. A count of
1024 2 means: skip the first and second, take the third, and so on.
1025 -Q <prefix> | --qvirtual <prefix>
1027 (Keyword: qvirtual; Multidrop only)
1028 The string prefix assigned to this option will be removed from
1029 the user name found in the header specified with the envelope
1030 option (before doing multidrop name mapping or localdomain
1031 checking, if either is applicable). This option is useful if you
1032 are using fetchmail to collect the mail for an entire domain and
1033 your ISP (or your mail redirection provider) is using qmail.
1034 One of the basic features of qmail is the Delivered-To: message
1035 header. Whenever qmail delivers a message to a local mailbox it
1036 puts the username and hostname of the envelope recipient on this
1037 line. The major reason for this is to prevent mail loops. To
1038 set up qmail to batch mail for a disconnected site the ISP-mail‐
1039 host will have normally put that site in its 'Virtualhosts' con‐
1040 trol file so it will add a prefix to all mail addresses for this
1041 site. This results in mail sent to 'username@userhost.user‐
1042 dom.dom.com' having a Delivered-To: line of the form:
1043 Delivered-To: mbox-userstr-username@userhost.example.com
1045 The ISP can make the 'mbox-userstr-' prefix anything they choose
1047 but a string matching the user host name is likely. By using
1048 the option 'envelope Delivered-To:' you can make fetchmail reli‐
1049 ably identify the original envelope recipient, but you have to
1050 strip the 'mbox-userstr-' prefix to deliver to the correct user.
1051 This is what this option is for.
1052 --configdump
1054 Parse the ~/.fetchmailrc file, interpret any command-line
1055 options specified, and dump a configuration report to standard
1056 output. The configuration report is a data structure assignment
1057 in the language Python. This option is meant to be used with an
1058 interactive ~/.fetchmailrc editor like fetchmailconf, written in
1059 Python.
1060 -y | --yydebug
1062 Enables parser debugging, this option is meant to be used by
1063 developers only.
1064 Removed Options
1067 -T | --netsec
1068 Removed before version 6.3.0, the required underlying inet6_apps
1069 library had been discontinued and is no longer available.
1070
1073 All modes except ETRN require authentication of the client to the
1074 server. Normal user authentication in fetchmail is very much like the
1075 authentication mechanism of ftp(1). The correct user-id and password
1076 depend upon the underlying security system at the mailserver.
1077 If the mailserver is a Unix machine on which you have an ordinary user
1079 account, your regular login name and password are used with fetchmail.
1080 If you use the same login name on both the server and the client
1081 machines, you needn't worry about specifying a user-id with the -u
1082 option -- the default behavior is to use your login name on the client
1083 machine as the user-id on the server machine. If you use a different
1084 login name on the server machine, specify that login name with the -u
1085 option. e.g. if your login name is 'jsmith' on a machine named 'mail‐
1086 grunt', you would start fetchmail as follows:
1087 fetchmail -u jsmith mailgrunt
1089 The default behavior of fetchmail is to prompt you for your mailserver
1091 password before the connection is established. This is the safest way
1092 to use fetchmail and ensures that your password will not be compro‐
1093 mised. You may also specify your password in your ~/.fetchmailrc file.
1094 This is convenient when using fetchmail in daemon mode or with scripts.
1095 Using netrc files
1098 If you do not specify a password, and fetchmail cannot extract one from
1099 your ~/.fetchmailrc file, it will look for a ~/.netrc file in your home
1100 directory before requesting one interactively; if an entry matching the
1101 mailserver is found in that file, the password will be used. Fetchmail
1102 first looks for a match on poll name; if it finds none, it checks for a
1103 match on via name. See the ftp(1) man page for details of the syntax
1104 of the ~/.netrc file. To show a practical example, a .netrc might look
1105 like this:
1106 machine hermes.example.org
1108 login joe
1109 password topsecret
1110 You can repeat this block with different user information if you need
1112 to provide more than one password.
1113 This feature may allow you to avoid duplicating password information in
1115 more than one file.
1116 On mailservers that do not provide ordinary user accounts, your user-id
1118 and password are usually assigned by the server administrator when you
1119 apply for a mailbox on the server. Contact your server administrator
1120 if you don't know the correct user-id and password for your mailbox
1121 account.
1122
1124 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
1125 independent authentication using the .rhosts file on the mailserver
1126 side. Under this RPOP variant, a fixed per-user ID equivalent to a
1127 password was sent in clear over a link to a reserved port, with the
1128 command RPOP rather than PASS to alert the server that it should do
1129 special checking. RPOP is supported by fetchmail (you can specify
1130 'protocol RPOP' to have the program send 'RPOP' rather than 'PASS') but
1131 its use is strongly discouraged, and support will be removed from a
1132 future fetchmail version. This facility was vulnerable to spoofing and
1133 was withdrawn in RFC1460.
1134 RFC1460 introduced APOP authentication. In this variant of POP3, you
1136 register an APOP password on your server host (on some servers, the
1137 program to do this is called popauth(8)). You put the same password in
1138 your ~/.fetchmailrc file. Each time fetchmail logs in, it sends an MD5
1139 hash of your password and the server greeting time to the server, which
1140 can verify it by checking its authorization database.
1141 Note that APOP is no longer considered resistant against man-in-the-
1143 middle attacks.
1144 RETR or TOP
1146 fetchmail makes some efforts to make the server believe messages had
1147 not been retrieved, by using the TOP command with a large number of
1148 lines when possible. TOP is a command that retrieves the full header
1149 and a fetchmail-specified amount of body lines. It is optional and
1150 therefore not implemented by all servers, and some are known to imple‐
1151 ment it improperly. On many servers however, the RETR command which
1152 retrieves the full message with header and body, sets the "seen" flag
1153 (for instance, in a web interface), whereas the TOP command does not do
1154 that.
1155 fetchmail will always use the RETR command if "fetchall" is set.
1157 fetchmail will also use the RETR command if "keep" is set and "uidl" is
1158 unset. Finally, fetchmail will use the RETR command on Maillennium
1159 POP3/PROXY servers (used by Comcast) to avoid a deliberate TOP misin‐
1160 terpretation in this server that causes message corruption.
1161 In all other cases, fetchmail will use the TOP command. This implies
1163 that in "keep" setups, "uidl" must be set if "TOP" is desired.
1164 Note that this description is true for the current version of fetch‐
1166 mail, but the behavior may change in future versions. In particular,
1167 fetchmail may prefer the RETR command because the TOP command causes
1168 much grief on some servers and is only optional.
1169
1171 If your fetchmail was built with Kerberos support and you specify Ker‐
1172 beros authentication (either with --auth or the .fetchmailrc option
1173 authenticate kerberos_v4) it will try to get a Kerberos ticket from the
1174 mailserver at the start of each query. Note: if either the pollname or
1175 via name is 'hesiod', fetchmail will try to use Hesiod to look up the
1176 mailserver.
1177 If you use POP3 or IMAP with GSSAPI authentication, fetchmail will
1179 expect the server to have RFC1731- or RFC1734-conforming GSSAPI capa‐
1180 bility, and will use it. Currently this has only been tested over Ker‐
1181 beros V, so you're expected to already have a ticket-granting ticket.
1182 You may pass a username different from your principal name using the
1183 standard --user command or by the .fetchmailrc option user.
1184 If your IMAP daemon returns the PREAUTH response in its greeting line,
1186 fetchmail will notice this and skip the normal authentication step.
1187 This can be useful, e.g. if you start imapd explicitly using ssh. In
1188 this case you can declare the authentication value 'ssh' on that site
1189 entry to stop .fetchmail from asking you for a password when it starts
1190 up.
1191 If you use client authentication with TLS1 and your IMAP daemon returns
1193 the AUTH=EXTERNAL response, fetchmail will notice this and will use the
1194 authentication shortcut and will not send the passphrase. In this case
1195 you can declare the authentication value 'external'
1196 on that site to stop fetchmail from asking you for a password when it
1197 starts up.
1198 If you are using POP3, and the server issues a one-time-password chal‐
1200 lenge conforming to RFC1938, fetchmail will use your password as a pass
1201 phrase to generate the required response. This avoids sending secrets
1202 over the net unencrypted.
1203 Compuserve's RPA authentication is supported. If you compile in the
1205 support, fetchmail will try to perform an RPA pass-phrase authentica‐
1206 tion instead of sending over the password en clair if it detects "@com‐
1207 puserve.com" in the hostname.
1208 If you are using IMAP, Microsoft's NTLM authentication (used by Micro‐
1210 soft Exchange) is supported. If you compile in the support, fetchmail
1211 will try to perform an NTLM authentication (instead of sending over the
1212 password en clair) whenever the server returns AUTH=NTLM in its capa‐
1213 bility response. Specify a user option value that looks like
1214 'user@domain': the part to the left of the @ will be passed as the
1215 username and the part to the right as the NTLM domain.
1216 Secure Socket Layers (SSL) and Transport Layer Security (TLS)
1219 transport. Additionally, POP3 and IMAP retrival can also negotiate
1220 SSL/TLS by means of STARTTLS (or STLS).
1221 Note that fetchmail currently uses the OpenSSL library, which is se‐
1223 verely underdocumented, so failures may occur just because the program‐
1224 mers are not aware of OpenSSL's requirement of the day. For instance,
1225 since v6.3.16, fetchmail calls OpenSSL_add_all_algorithms(), which is
1226 necessary to support certificates using SHA256 on OpenSSL 0.9.8 -- this
1227 information is deeply hidden in the documentation and not at all obvi‐
1228 ous. Please do not hesitate to report subtle SSL failures.
1229 You can access SSL encrypted services by specifying the options start‐
1231 ing with --ssl, such as --ssl, --sslproto, --sslcertck, and others.
1232 You can also do this using the corresponding user options in the
1233 .fetchmailrc file. Some services, such as POP3 and IMAP, have differ‐
1234 ent well known ports defined for the SSL encrypted services. The
1235 encrypted ports will be selected automatically when SSL is enabled and
1236 no explicit port is specified. Also, the --sslcertck command line or
1237 sslcertck run control file option should be used to force strict cer‐
1238 tificate checking - see below.
1239 If SSL is not configured, fetchmail will usually opportunistically try
1241 to use STARTTLS. STARTTLS can be enforced by using --sslproto auto and
1242 defeated by using --sslproto ''. TLS connections use the same port as
1243 the unencrypted version of the protocol and negotiate TLS via special
1244 command. The --sslcertck command line or sslcertck run control file
1245 option should be used to force strict certificate checking - see below.
1246 --sslcertck is recommended: When connecting to an SSL or TLS encrypted
1248 server, the server presents a certificate to the client for validation.
1249 The certificate is checked to verify that the common name in the cer‐
1250 tificate matches the name of the server being contacted and that the
1251 effective and expiration dates in the certificate indicate that it is
1252 currently valid. If any of these checks fail, a warning message is
1253 printed, but the connection continues. The server certificate does not
1254 need to be signed by any specific Certifying Authority and may be a
1255 "self-signed" certificate. If the --sslcertck command line option or
1256 sslcertck run control file option is used, fetchmail will instead abort
1257 if any of these checks fail, because it must assume that there is a
1258 man-in-the-middle attack in this scenario, hence fetchmail must not
1259 expose cleartext passwords. Use of the sslcertck or --sslcertck option
1260 is therefore advised.
1261 Some SSL encrypted servers may request a client side certificate. A
1263 client side public SSL certificate and private SSL key may be speci‐
1264 fied. If requested by the server, the client certificate is sent to
1265 the server for validation. Some servers may require a valid client
1266 certificate and may refuse connections if a certificate is not provided
1267 or if the certificate is not valid. Some servers may require client
1268 side certificates be signed by a recognized Certifying Authority. The
1269 format for the key files and the certificate files is that required by
1270 the underlying SSL libraries (OpenSSL in the general case).
1271 A word of care about the use of SSL: While above mentioned setup with
1273 self-signed server certificates retrieved over the wires can protect
1274 you from a passive eavesdropper, it doesn't help against an active
1275 attacker. It's clearly an improvement over sending the passwords in
1276 clear, but you should be aware that a man-in-the-middle attack is triv‐
1277 ially possible (in particular with tools such as dsniff ⟨http://
1278 monkey.org/~dugsong/dsniff/⟩, ). Use of strict certificate checking
1279 with a certification authority recognized by server and client, or per‐
1280 haps of an SSH tunnel (see below for some examples) is preferable if
1281 you care seriously about the security of your mailbox and passwords.
1282 ESMTP AUTH
1285 fetchmail also supports authentication to the ESMTP server on the
1286 client side according to RFC 2554. You can specify a name/password
1287 pair to be used with the keywords 'esmtpname' and 'esmtppassword'; the
1288 former defaults to the username of the calling user.
1289
1292 Introducing the daemon mode
1293 In daemon mode, fetchmail puts itself into the background and runs for‐
1294 ever, querying each specified host and then sleeping for a given
1295 polling interval.
1296 Starting the daemon mode
1298 There are several ways to make fetchmail work in daemon mode. On the
1299 command line, --daemon <interval> or -d <interval> option runs fetch‐
1300 mail in daemon mode. You must specify a numeric argument which is a
1301 polling interval (time to wait after completing a whole poll cycle with
1302 the last server and before starting the next poll cycle with the first
1303 server) in seconds.
1304 Example: simply invoking
1306 fetchmail -d 900
1308 will, therefore, poll all the hosts described in your ~/.fetchmailrc
1310 file (except those explicitly excluded with the 'skip' verb) a bit less
1311 often than once every 15 minutes (exactly: 15 minutes + time that the
1312 poll takes).
1313 It is also possible to set a polling interval in your ~/.fetchmailrc
1315 file by saying 'set daemon <interval>', where <interval> is an integer
1316 number of seconds. If you do this, fetchmail will always start in dae‐
1317 mon mode unless you override it with the command-line option --daemon 0
1318 or -d0.
1319 Only one daemon process is permitted per user; in daemon mode, fetch‐
1321 mail sets up a per-user lockfile to guarantee this. (You can however
1322 cheat and set the FETCHMAILHOME environment variable to overcome this
1323 setting, but in that case, it is your responsibility to make sure you
1324 aren't polling the same server with two processes at the same time.)
1325 Awakening the background daemon
1327 Normally, calling fetchmail with a daemon in the background sends a
1328 wake-up signal to the daemon and quits without output. The background
1329 daemon then starts its next poll cycle immediately. The wake-up sig‐
1330 nal, SIGUSR1, can also be sent manually. The wake-up action also clears
1331 any 'wedged' flags indicating that connections have wedged due to
1332 failed authentication or multiple timeouts.
1333 Terminating the background daemon
1335 The option -q or --quit will kill a running daemon process instead of
1336 waking it up (if there is no such process, fetchmail will notify you).
1337 If the --quit option appears last on the command line, fetchmail will
1338 kill the running daemon process and then quit. Otherwise, fetchmail
1339 will first kill a running daemon process and then continue running with
1340 the other options.
1341 Useful options for daemon mode
1343 The -L <filename> or --logfile <filename> option (keyword: set logfile)
1344 is only effective when fetchmail is detached and in daemon mode. Note
1345 that the logfile must exist before fetchmail is run, you can use the
1346 touch(1) command with the filename as its sole argument to create it.
1347 This option allows you to redirect status messages into a specified
1348 logfile (follow the option with the logfile name). The logfile is
1349 opened for append, so previous messages aren't deleted. This is pri‐
1350 marily useful for debugging configurations. Note that fetchmail does
1351 not detect if the logfile is rotated, the logfile is only opened once
1352 when fetchmail starts. You need to restart fetchmail after rotating the
1353 logfile and before compressing it (if applicable).
1354 The --syslog option (keyword: set syslog) allows you to redirect status
1356 and error messages emitted to the syslog(3) system daemon if available.
1357 Messages are logged with an id of fetchmail, the facility LOG_MAIL, and
1358 priorities LOG_ERR, LOG_ALERT or LOG_INFO. This option is intended for
1359 logging status and error messages which indicate the status of the dae‐
1360 mon and the results while fetching mail from the server(s). Error mes‐
1361 sages for command line options and parsing the .fetchmailrc file are
1362 still written to stderr, or to the specified log file. The --nosyslog
1363 option turns off use of syslog(3), assuming it's turned on in the
1364 ~/.fetchmailrc file. This option is overridden, in certain situations,
1365 by --logfile (which see).
1366 The -N or --nodetach option suppresses backgrounding and detachment of
1368 the daemon process from its control terminal. This is useful for
1369 debugging or when fetchmail runs as the child of a supervisor process
1370 such as init(8) or Gerrit Pape's runit(8). Note that this also causes
1371 the logfile option to be ignored.
1372 Note that while running in daemon mode polling a POP2 or IMAP2bis
1374 server, transient errors (such as DNS failures or sendmail delivery
1375 refusals) may force the fetchall option on for the duration of the next
1376 polling cycle. This is a robustness feature. It means that if a mes‐
1377 sage is fetched (and thus marked seen by the mailserver) but not deliv‐
1378 ered locally due to some transient error, it will be re-fetched during
1379 the next poll cycle. (The IMAP logic doesn't delete messages until
1380 they're delivered, so this problem does not arise.)
1381 If you touch or change the ~/.fetchmailrc file while fetchmail is run‐
1383 ning in daemon mode, this will be detected at the beginning of the next
1384 poll cycle. When a changed ~/.fetchmailrc is detected, fetchmail
1385 rereads it and restarts from scratch (using exec(2); no state informa‐
1386 tion is retained in the new instance). Note that if fetchmail needs to
1387 query for passwords, of that if you break the ~/.fetchmailrc file's
1388 syntax, the new instance will softly and silently vanish away on
1389 startup.
1390
1393 The --postmaster <name> option (keyword: set postmaster) specifies the
1394 last-resort username to which multidrop mail is to be forwarded if no
1395 matching local recipient can be found. It is also used as destination
1396 of undeliverable mail if the 'bouncemail' global option is off and
1397 additionally for spam-blocked mail if the 'bouncemail' global option is
1398 off and the 'spambounce' global option is on. This option defaults to
1399 the user who invoked fetchmail. If the invoking user is root, then the
1400 default of this option is the user 'postmaster'. Setting postmaster to
1401 the empty string causes such mail as described above to be discarded -
1402 this however is usually a bad idea. See also the description of the
1403 'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.
1404 The --nobounce behaves like the "set no bouncemail" global option,
1406 which see.
1407 The --invisible option (keyword: set invisible) tries to make fetchmail
1409 invisible. Normally, fetchmail behaves like any other MTA would -- it
1410 generates a Received header into each message describing its place in
1411 the chain of transmission, and tells the MTA it forwards to that the
1412 mail came from the machine fetchmail itself is running on. If the
1413 invisible option is on, the Received header is suppressed and fetchmail
1414 tries to spoof the MTA it forwards to into thinking it came directly
1415 from the mailserver host.
1416 The --showdots option (keyword: set showdots) forces fetchmail to show
1418 progress dots even if the output goes to a file or fetchmail is not in
1419 verbose mode. Fetchmail shows the dots by default when run in --ver‐
1420 bose mode and output goes to console. This option is ignored in
1421 --silent mode.
1422 By specifying the --tracepolls option, you can ask fetchmail to add
1424 information to the Received header on the form "polling {label} account
1425 {user}", where {label} is the account label (from the specified rcfile,
1426 normally ~/.fetchmailrc) and {user} is the username which is used to
1427 log on to the mail server. This header can be used to make filtering
1428 email where no useful header information is available and you want mail
1429 from different accounts sorted into different mailboxes (this could,
1430 for example, occur if you have an account on the same server running a
1431 mailing list, and are subscribed to the list using that account). The
1432 default is not adding any such header. In .fetchmailrc, this is called
1433 'tracepolls'.
1434
1437 The protocols fetchmail uses to talk to mailservers are next to bullet‐
1438 proof. In normal operation forwarding to port 25, no message is ever
1439 deleted (or even marked for deletion) on the host until the SMTP lis‐
1440 tener on the client side has acknowledged to fetchmail that the message
1441 has been either accepted for delivery or rejected due to a spam block.
1442 When forwarding to an MDA, however, there is more possibility of error.
1444 Some MDAs are 'safe' and reliably return a nonzero status on any deliv‐
1445 ery error, even one due to temporary resource limits. The maildrop(1)
1446 program is like this; so are most programs designed as mail transport
1447 agents, such as sendmail(1), including the sendmail wrapper of Postfix
1448 and exim(1). These programs give back a reliable positive acknowledge‐
1449 ment and can be used with the mda option with no risk of mail loss.
1450 Unsafe MDAs, though, may return 0 even on delivery failure. If this
1451 happens, you will lose mail.
1452 The normal mode of fetchmail is to try to download only 'new' messages,
1454 leaving untouched (and undeleted) messages you have already read
1455 directly on the server (or fetched with a previous fetchmail --keep).
1456 But you may find that messages you've already read on the server are
1457 being fetched (and deleted) even when you don't specify --all. There
1458 are several reasons this can happen.
1459 One could be that you're using POP2. The POP2 protocol includes no
1461 representation of 'new' or 'old' state in messages, so fetchmail must
1462 treat all messages as new all the time. But POP2 is obsolete, so this
1463 is unlikely.
1464 A potential POP3 problem might be servers that insert messages in the
1466 middle of mailboxes (some VMS implementations of mail are rumored to do
1467 this). The fetchmail code assumes that new messages are appended to
1468 the end of the mailbox; when this is not true it may treat some old
1469 messages as new and vice versa. Using UIDL whilst setting fastuidl 0
1470 might fix this, otherwise, consider switching to IMAP.
1471 Yet another POP3 problem is that if they can't make tempfiles in the
1473 user's home directory, some POP3 servers will hand back an undocumented
1474 response that causes fetchmail to spuriously report "No mail".
1475 The IMAP code uses the presence or absence of the server flag \Seen to
1477 decide whether or not a message is new. This isn't the right thing to
1478 do, fetchmail should check the UIDVALIDITY and use UID, but it doesn't
1479 do that yet. Under Unix, it counts on your IMAP server to notice the
1480 BSD-style Status flags set by mail user agents and set the \Seen flag
1481 from them when appropriate. All Unix IMAP servers we know of do this,
1482 though it's not specified by the IMAP RFCs. If you ever trip over a
1483 server that doesn't, the symptom will be that messages you have already
1484 read on your host will look new to the server. In this (unlikely)
1485 case, only messages you fetched with fetchmail --keep will be both
1486 undeleted and marked old.
1487 In ETRN and ODMR modes, fetchmail does not actually retrieve messages;
1489 instead, it asks the server's SMTP listener to start a queue flush to
1490 the client via SMTP. Therefore it sends only undelivered messages.
1491
1494 Many SMTP listeners allow administrators to set up 'spam filters' that
1495 block unsolicited email from specified domains. A MAIL FROM or DATA
1496 line that triggers this feature will elicit an SMTP response which
1497 (unfortunately) varies according to the listener.
1498 Newer versions of sendmail return an error code of 571.
1500 According to RFC2821, the correct thing to return in this situation is
1502 550 "Requested action not taken: mailbox unavailable" (the draft adds
1503 "[E.g., mailbox not found, no access, or command rejected for policy
1504 reasons].").
1505 Older versions of the exim MTA return 501 "Syntax error in parameters
1507 or arguments".
1508 The postfix MTA runs 554 as an antispam response.
1510 Zmailer may reject code with a 500 response (followed by an enhanced
1512 status code that contains more information).
1513 Return codes which fetchmail treats as antispam responses and discards
1515 the message can be set with the 'antispam' option. This is one of the
1516 only three circumstance under which fetchmail ever discards mail (the
1517 others are the 552 and 553 errors described below, and the suppression
1518 of multidropped messages with a message-ID already seen).
1519 If fetchmail is fetching from an IMAP server, the antispam response
1521 will be detected and the message rejected immediately after the headers
1522 have been fetched, without reading the message body. Thus, you won't
1523 pay for downloading spam message bodies.
1524 By default, the list of antispam responses is empty.
1526 If the spambounce global option is on, mail that is spam-blocked trig‐
1528 gers an RFC1892/RFC1894 bounce message informing the originator that we
1529 do not accept mail from it. See also BUGS.
1530
1533 Besides the spam-blocking described above, fetchmail takes special
1534 actions on the following SMTP/ESMTP error responses
1535 452 (insufficient system storage)
1537 Leave the message in the server mailbox for later retrieval.
1538 552 (message exceeds fixed maximum message size)
1540 Delete the message from the server. Send bounce-mail to the orig‐
1541 inator.
1542 553 (invalid sending domain)
1544 Delete the message from the server. Don't even try to send
1545 bounce-mail to the originator.
1546 Other errors trigger bounce mail back to the originator. See also BUGS.
1548
1551 The preferred way to set up fetchmail is to write a .fetchmailrc file
1552 in your home directory (you may do this directly, with a text editor,
1553 or indirectly via fetchmailconf). When there is a conflict between the
1554 command-line arguments and the arguments in this file, the command-line
1555 arguments take precedence.
1556 To protect the security of your passwords, your ~/.fetchmailrc may not
1558 normally have more than 0700 (u=rwx,g=,o=) permissions; fetchmail will
1559 complain and exit otherwise (this check is suppressed when --version is
1560 on).
1561 You may read the .fetchmailrc file as a list of commands to be executed
1563 when fetchmail is called with no arguments.
1564 Run Control Syntax
1566 Comments begin with a '#' and extend through the end of the line. Oth‐
1567 erwise the file consists of a series of server entries or global option
1568 statements in a free-format, token-oriented syntax.
1569 There are four kinds of tokens: grammar keywords, numbers (i.e. decimal
1571 digit sequences), unquoted strings, and quoted strings. A quoted
1572 string is bounded by double quotes and may contain whitespace (and
1573 quoted digits are treated as a string). Note that quoted strings will
1574 also contain line feed characters if they run across two or more lines,
1575 unless you use a backslash to join lines (see below). An unquoted
1576 string is any whitespace-delimited token that is neither numeric,
1577 string quoted nor contains the special characters ',', ';', ':', or
1578 '='.
1579 Any amount of whitespace separates tokens in server entries, but is
1581 otherwise ignored. You may use backslash escape sequences (\n for LF,
1582 \t for HT, \b for BS, \r for CR, \nnn for decimal (where nnn cannot
1583 start with a 0), \0ooo for octal, and \xhh for hex) to embed non-print‐
1584 able characters or string delimiters in strings. In quoted strings, a
1585 backslash at the very end of a line will cause the backslash itself and
1586 the line feed (LF or NL, new line) character to be ignored, so that you
1587 can wrap long strings. Without the backslash at the line end, the line
1588 feed character would become part of the string.
1589 Warning: while these resemble C-style escape sequences, they are not
1591 the same. fetchmail only supports these eight styles. C supports more
1592 escape sequences that consist of backslash (\) and a single character,
1593 but does not support decimal codes and does not require the leading 0
1594 in octal notation. Example: fetchmail interprets \233 the same as \xE9
1595 (Latin small letter e with acute), where C would interpret \233 as
1596 octal 0233 = \x9B (CSI, control sequence introducer).
1597 Each server entry consists of one of the keywords 'poll' or 'skip',
1599 followed by a server name, followed by server options, followed by any
1600 number of user (or username) descriptions, followed by user options.
1601 Note: the most common cause of syntax errors is mixing up user and
1602 server options or putting user options before the user descriptions.
1603 For backward compatibility, the word 'server' is a synonym for 'poll'.
1605 You can use the noise keywords 'and', 'with', 'has', 'wants', and
1607 'options' anywhere in an entry to make it resemble English. They're
1608 ignored, but but can make entries much easier to read at a glance. The
1609 punctuation characters ':', ';' and ',' are also ignored.
1610 Poll vs. Skip
1612 The 'poll' verb tells fetchmail to query this host when it is run with
1613 no arguments. The 'skip' verb tells fetchmail not to poll this host
1614 unless it is explicitly named on the command line. (The 'skip' verb
1615 allows you to experiment with test entries safely, or easily disable
1616 entries for hosts that are temporarily down.)
1617 Keyword/Option Summary
1619 Here are the legal options. Keyword suffixes enclosed in square brack‐
1620 ets are optional. Those corresponding to short command-line options
1621 are followed by '-' and the appropriate option letter. If option is
1622 only relevant to a single mode of operation, it is noted as 's' or 'm'
1623 for singledrop- or multidrop-mode, respectively.
1624 Here are the legal global options:
1626 Keyword Opt Mode Function
1629 ────────────────────────────────────────────────────────────────────
1630 set daemon -d Set a background poll interval in
1631 seconds.
1632 set postmaster Give the name of the last-resort
1633 mail recipient (default: user run‐
1634 ning fetchmail, "postmaster" if
1635 run by the root user)
1636 set bouncemail Direct error mail to the sender
1637 (default)
1638 set no bouncemail Direct error mail to the local
1639 postmaster (as per the 'postmas‐
1640 ter' global option above).
1641 set no spambounce Do not bounce spam-blocked mail
1642 (default).
1643 set spambounce Bounce blocked spam-blocked mail
1644 (as per the 'antispam' user
1645 option) back to the destination as
1646 indicated by the 'bouncemail'
1647 global option. Warning: Do not
1648 use this to bounce spam back to
1649 the sender - most spam is sent
1650 with false sender address and thus
1651 this option hurts innocent
1652 bystanders.
1653 set no softbounce Delete permanently undeliverable
1654 mail. It is recommended to use
1655 this option if the configuration
1656 has been thoroughly tested.
1657 set softbounce Keep permanently undeliverable
1658 mail as though a temporary error
1659 had occurred (default).
1660 set logfile -L Name of a file to append error and
1661 status messages to. Only effec‐
1662 tive in daemon mode and if fetch‐
1663 mail detaches. If effective,
1664 overrides set syslog.
1665 set idfile -i Name of the file to store UID
1666 lists in.
1667 set syslog Do error logging through sys‐
1668 log(3). May be overriden by set
1669 logfile.
1670 set no syslog Turn off error logging through
1671 syslog(3). (default)
1672 set properties String value that is ignored by
1673 fetchmail (may be used by exten‐
1674 sion scripts).
1675 Here are the legal server options:
1677 Keyword Opt Mode Function
1681 ─────────────────────────────────────────────────────────────────
1682 via Specify DNS name of mailserver,
1683 overriding poll name
1684 proto[col] -p Specify protocol (case insensi‐
1685 tive): POP2, POP3, IMAP, APOP,
1686 KPOP
1687 local[domains] m Specify domain(s) to be regarded
1688 as local
1689 port Specify TCP/IP service port (obso‐
1690 lete, use 'service' instead).
1691 service -P Specify service name (a numeric
1692 value is also allowed and consid‐
1693 ered a TCP/IP port number).
1694 auth[enticate] Set authentication type (default
1695 'any')
1696 timeout -t Server inactivity timeout in sec‐
1697 onds (default 300)
1698 envelope -E m Specify envelope-address header
1699 name
1700 no envelope m Disable looking for envelope
1701 address
1702 qvirtual -Q m Qmail virtual domain prefix to
1703 remove from user name
1704 aka m Specify alternate DNS names of
1705 mailserver
1706 interface -I specify IP interface(s) that must
1707 be up for server poll to take
1708 place
1709 monitor -M Specify IP address to monitor for
1710 activity
1711 plugin Specify command through which to
1712 make server connections.
1713 plugout Specify command through which to
1714 make listener connections.
1715 dns m Enable DNS lookup for multidrop
1716 (default)
1717 no dns m Disable DNS lookup for multidrop
1718 checkalias m Do comparison by IP address for
1719 multidrop
1720 no checkalias m Do comparison by name for mul‐
1721 tidrop (default)
1722 uidl -U Force POP3 to use client-side
1723 UIDLs (recommended)
1724 no uidl Turn off POP3 use of client-side
1725 UIDLs (default)
1726 interval Only check this site every N poll
1727 cycles; N is a numeric argument.
1728 tracepolls Add poll tracing information to
1729 the Received header
1730 principal Set Kerberos principal (only use‐
1731 ful with IMAP and kerberos)
1732 esmtpname Set name for RFC2554 authentica‐
1733 tion to the ESMTP server.
1734 esmtppassword Set password for RFC2554 authenti‐
1735 cation to the ESMTP server.
1736 bad-header How to treat messages with a bad
1737 header. Can be reject (default) or
1738 accept.
1739 Here are the legal user descriptions and options:
1741 Keyword Opt Mode Function
1744 ───────────────────────────────────────────────────────────────────
1745 user[name] -u This is the user description and
1746 must come first after server
1747 description and after possible
1748 server options, and before user
1749 options.
1750 It sets the remote user name if by
1751 itself or followed by 'there', or
1752 the local user name if followed by
1753 'here'.
1754 is Connect local and remote user
1757 names
1758 to Connect local and remote user
1759 names
1760 pass[word] Specify remote account password
1761 ssl Connect to server over the speci‐
1762 fied base protocol using SSL
1763 encryption
1764 sslcert Specify file for client side pub‐
1765 lic SSL certificate
1766 sslcertfile Specify file with trusted CA cer‐
1767 tificates
1768 sslcertpath Specify c_rehash-ed directory with
1769 trusted CA certificates.
1770 sslkey Specify file for client side pri‐
1771 vate SSL key
1772 sslproto Force ssl protocol for connection
1773 folder -r Specify remote folder to query
1774 smtphost -S Specify smtp host(s) to forward to
1775 fetchdomains m Specify domains for which mail
1776 should be fetched
1777 smtpaddress -D Specify the domain to be put in
1778 RCPT TO lines
1779 smtpname Specify the user and domain to be
1780 put in RCPT TO lines
1781 antispam -Z Specify what SMTP returns are
1782 interpreted as spam-policy blocks
1783 mda -m Specify MDA for local delivery
1784 bsmtp Specify BSMTP batch file to append
1785 to
1786 preconnect Command to be executed before each
1787 connection
1788 postconnect Command to be executed after each
1789 connection
1790 keep -k Don't delete seen messages from
1791 server (for POP3, uidl is recom‐
1792 mended)
1793 flush -F Flush all seen messages before
1794 querying (DANGEROUS)
1795 limitflush Flush all oversized messages
1796 before querying
1797 fetchall -a Fetch all messages whether seen or
1798 not
1799 rewrite Rewrite destination addresses for
1800 reply (default)
1801 stripcr Strip carriage returns from ends
1802 of lines
1803 forcecr Force carriage returns at ends of
1804 lines
1805 pass8bits Force BODY=8BITMIME to ESMTP lis‐
1806 tener
1807 dropstatus Strip Status and X-Mozilla-Status
1808 lines out of incoming mail
1809 dropdelivered Strip Delivered-To lines out of
1810 incoming mail
1811 mimedecode Convert quoted-printable to 8-bit
1812 in MIME messages
1813 idle Idle waiting for new messages
1814 after each poll (IMAP only)
1815 no keep -K Delete seen messages from server
1816 (default)
1817 no flush Don't flush all seen messages
1818 before querying (default)
1819 no fetchall Retrieve only new messages
1820 (default)
1821 no rewrite Don't rewrite headers
1822 no stripcr Don't strip carriage returns
1823 (default)
1824 no forcecr Don't force carriage returns at
1825 EOL (default)
1826 no pass8bits Don't force BODY=8BITMIME to ESMTP
1827 listener (default)
1828 no dropstatus Don't drop Status headers
1829 (default)
1830 no dropdelivered Don't drop Delivered-To headers
1833 (default)
1834 no mimedecode Don't convert quoted-printable to
1835 8-bit in MIME messages (default)
1836 no idle Don't idle waiting for new mes‐
1837 sages after each poll (IMAP only)
1838 limit -l Set message size limit
1839 warnings -w Set message size warning interval
1840 batchlimit -b Max # messages to forward in sin‐
1841 gle connect
1842 fetchlimit -B Max # messages to fetch in single
1843 connect
1844 fetchsizelimit Max # message sizes to fetch in
1845 single transaction
1846 fastuidl Use binary search for first unseen
1847 message (POP3 only)
1848 expunge -e Perform an expunge on every #th
1849 message (IMAP and POP3 only)
1850 properties String value is ignored by fetch‐
1851 mail (may be used by extension
1852 scripts)
1853 All user options must begin with a user description (user or username
1855 option) and follow all server descriptions and options.
1856 In the .fetchmailrc file, the 'envelope' string argument may be pre‐
1858 ceded by a whitespace-separated number. This number, if specified, is
1859 the number of such headers to skip over (that is, an argument of 1
1860 selects the second header of the given type). This is sometime useful
1861 for ignoring bogus envelope headers created by an ISP's local delivery
1862 agent or internal forwards (through mail inspection systems, for
1863 instance).
1864 Keywords Not Corresponding To Option Switches
1866 The 'folder' and 'smtphost' options (unlike their command-line equiva‐
1867 lents) can take a space- or comma-separated list of names following
1868 them.
1869 All options correspond to the obvious command-line arguments, except
1871 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1872 'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1873 'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1874 'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus', 'dropdeliv‐
1875 ered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle', and 'no
1876 envelope'.
1877 The 'via' option is for if you want to have more than one configuration
1879 pointing at the same site. If it is present, the string argument will
1880 be taken as the actual DNS name of the mailserver host to query. This
1881 will override the argument of poll, which can then simply be a distinct
1882 label for the configuration (e.g. what you would give on the command
1883 line to explicitly query this host).
1884 The 'interval' option (which takes a numeric argument) allows you to
1886 poll a server less frequently than the basic poll interval. If you say
1887 'interval N' the server this option is attached to will only be queried
1888 every N poll intervals.
1889 Singledrop vs. Multidrop options
1891 Please ensure you read the section titled THE USE AND ABUSE OF MUL‐
1892 TIDROP MAILBOXES if you intend to use multidrop mode.
1893 The 'is' or 'to' keywords associate the following local (client)
1895 name(s) (or server-name to client-name mappings separated by =) with
1896 the mailserver user name in the entry. If an is/to list has '*' as its
1897 last name, unrecognized names are simply passed through. Note that
1898 until fetchmail version 6.3.4 inclusively, these lists could only con‐
1899 tain local parts of user names (fetchmail would only look at the part
1900 before the @ sign). fetchmail versions 6.3.5 and newer support full
1901 addresses on the left hand side of these mappings, and they take prece‐
1902 dence over any 'localdomains', 'aka', 'via' or similar mappings.
1903 A single local name can be used to support redirecting your mail when
1905 your username on the client machine is different from your name on the
1906 mailserver. When there is only a single local name, mail is forwarded
1907 to that local username regardless of the message's Received, To, Cc,
1908 and Bcc headers. In this case, fetchmail never does DNS lookups.
1909 When there is more than one local name (or name mapping), fetchmail
1911 looks at the envelope header, if configured, and otherwise at the
1912 Received, To, Cc, and Bcc headers of retrieved mail (this is 'multidrop
1913 mode'). It looks for addresses with hostname parts that match your
1914 poll name or your 'via', 'aka' or 'localdomains' options, and usually
1915 also for hostname parts which DNS tells it are aliases of the
1916 mailserver. See the discussion of 'dns', 'checkalias', 'localdomains',
1917 and 'aka' for details on how matching addresses are handled.
1918 If fetchmail cannot match any mailserver usernames or localdomain
1920 addresses, the mail will be bounced. Normally it will be bounced to
1921 the sender, but if the 'bouncemail' global option is off, the mail will
1922 go to the local postmaster instead. (see the 'postmaster' global
1923 option). See also BUGS.
1924 The 'dns' option (normally on) controls the way addresses from mul‐
1926 tidrop mailboxes are checked. On, it enables logic to check each host
1927 address that does not match an 'aka' or 'localdomains' declaration by
1928 looking it up with DNS. When a mailserver username is recognized
1929 attached to a matching hostname part, its local mapping is added to the
1930 list of local recipients.
1931 The 'checkalias' option (normally off) extends the lookups performed by
1933 the 'dns' keyword in multidrop mode, providing a way to cope with
1934 remote MTAs that identify themselves using their canonical name, while
1935 they're polled using an alias. When such a server is polled, checks to
1936 extract the envelope address fail, and fetchmail reverts to delivery
1937 using the To/Cc/Bcc headers (See below 'Header vs. Envelope
1938 addresses'). Specifying this option instructs fetchmail to retrieve
1939 all the IP addresses associated with both the poll name and the name
1940 used by the remote MTA and to do a comparison of the IP addresses.
1941 This comes in handy in situations where the remote server undergoes
1942 frequent canonical name changes, that would otherwise require modifica‐
1943 tions to the rcfile. 'checkalias' has no effect if 'no dns' is speci‐
1944 fied in the rcfile.
1945 The 'aka' option is for use with multidrop mailboxes. It allows you to
1947 pre-declare a list of DNS aliases for a server. This is an optimiza‐
1948 tion hack that allows you to trade space for speed. When fetchmail,
1949 while processing a multidrop mailbox, grovels through message headers
1950 looking for names of the mailserver, pre-declaring common ones can save
1951 it from having to do DNS lookups. Note: the names you give as argu‐
1952 ments to 'aka' are matched as suffixes -- if you specify (say) 'aka
1953 netaxs.com', this will match not just a hostname netaxs.com, but any
1954 hostname that ends with '.netaxs.com'; such as (say) pop3.netaxs.com
1955 and mail.netaxs.com.
1956 The 'localdomains' option allows you to declare a list of domains which
1958 fetchmail should consider local. When fetchmail is parsing address
1959 lines in multidrop modes, and a trailing segment of a host name matches
1960 a declared local domain, that address is passed through to the listener
1961 or MDA unaltered (local-name mappings are not applied).
1962 If you are using 'localdomains', you may also need to specify 'no enve‐
1964 lope', which disables fetchmail's normal attempt to deduce an envelope
1965 address from the Received line or X-Envelope-To header or whatever
1966 header has been previously set by 'envelope'. If you set 'no envelope'
1967 in the defaults entry it is possible to undo that in individual entries
1968 by using 'envelope <string>'. As a special case, 'envelope "Received"'
1969 restores the default parsing of Received lines.
1970 The password option requires a string argument, which is the password
1972 to be used with the entry's server.
1973 The 'preconnect' keyword allows you to specify a shell command to be
1975 executed just before each time fetchmail establishes a mailserver con‐
1976 nection. This may be useful if you are attempting to set up secure POP
1977 connections with the aid of ssh(1). If the command returns a nonzero
1978 status, the poll of that mailserver will be aborted.
1979 Similarly, the 'postconnect' keyword similarly allows you to specify a
1981 shell command to be executed just after each time a mailserver connec‐
1982 tion is taken down.
1983 The 'forcecr' option controls whether lines terminated by LF only are
1985 given CRLF termination before forwarding. Strictly speaking RFC821
1986 requires this, but few MTAs enforce the requirement it so this option
1987 is normally off (only one such MTA, qmail, is in significant use at
1988 time of writing).
1989 The 'stripcr' option controls whether carriage returns are stripped out
1991 of retrieved mail before it is forwarded. It is normally not necessary
1992 to set this, because it defaults to 'on' (CR stripping enabled) when
1993 there is an MDA declared but 'off' (CR stripping disabled) when for‐
1994 warding is via SMTP. If 'stripcr' and 'forcecr' are both on, 'stripcr'
1995 will override.
1996 The 'pass8bits' option exists to cope with Microsoft mail programs that
1998 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1999 this option off (the default) and such a header present, fetchmail
2000 declares BODY=7BIT to an ESMTP-capable listener; this causes problems
2001 for messages actually using 8-bit ISO or KOI-8 character sets, which
2002 will be garbled by having the high bits of all characters stripped. If
2003 'pass8bits' is on, fetchmail is forced to declare BODY=8BITMIME to any
2004 ESMTP-capable listener. If the listener is 8-bit-clean (as all the
2005 major ones now are) the right thing will probably result.
2006 The 'dropstatus' option controls whether nonempty Status and X-Mozilla-
2008 Status lines are retained in fetched mail (the default) or discarded.
2009 Retaining them allows your MUA to see what messages (if any) were
2010 marked seen on the server. On the other hand, it can confuse some new-
2011 mail notifiers, which assume that anything with a Status line in it has
2012 been seen. (Note: the empty Status lines inserted by some buggy POP
2013 servers are unconditionally discarded.)
2014 The 'dropdelivered' option controls whether Delivered-To headers will
2016 be kept in fetched mail (the default) or discarded. These headers are
2017 added by Qmail and Postfix mailservers in order to avoid mail loops but
2018 may get in your way if you try to "mirror" a mailserver within the same
2019 domain. Use with caution.
2020 The 'mimedecode' option controls whether MIME messages using the
2022 quoted-printable encoding are automatically converted into pure 8-bit
2023 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean lis‐
2024 tener (that includes all of the major MTAs like sendmail), then this
2025 will automatically convert quoted-printable message headers and data
2026 into 8-bit data, making it easier to understand when reading mail. If
2027 your e-mail programs know how to deal with MIME messages, then this
2028 option is not needed. The mimedecode option is off by default, because
2029 doing RFC2047 conversion on headers throws away character-set informa‐
2030 tion and can lead to bad results if the encoding of the headers differs
2031 from the body encoding.
2032 The 'idle' option is intended to be used with IMAP servers supporting
2034 the RFC2177 IDLE command extension, but does not strictly require it.
2035 If it is enabled, and fetchmail detects that IDLE is supported, an IDLE
2036 will be issued at the end of each poll. This will tell the IMAP server
2037 to hold the connection open and notify the client when new mail is
2038 available. If IDLE is not supported, fetchmail will simulate it by
2039 periodically issuing NOOP. If you need to poll a link frequently, IDLE
2040 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
2041 sequences. On the other hand, an IDLE connection will eat almost all of
2042 your fetchmail's time, because it will never drop the connection and
2043 allow other polls to occur unless the server times out the IDLE. It
2044 also doesn't work with multiple folders; only the first folder will
2045 ever be polled.
2046 The 'properties' option is an extension mechanism. It takes a string
2049 argument, which is ignored by fetchmail itself. The string argument
2050 may be used to store configuration information for scripts which
2051 require it. In particular, the output of '--configdump' option will
2052 make properties associated with a user entry readily available to a
2053 Python script.
2054 Miscellaneous Run Control Options
2056 The words 'here' and 'there' have useful English-like significance.
2057 Normally 'user eric is esr' would mean that mail for the remote user
2058 'eric' is to be delivered to 'esr', but you can make this clearer by
2059 saying 'user eric there is esr here', or reverse it by saying 'user esr
2060 here is eric there'
2061 Legal protocol identifiers for use with the 'protocol' keyword are:
2063 auto (or AUTO) (legacy, to be removed from future release)
2065 pop2 (or POP2) (legacy, to be removed from future release)
2066 pop3 (or POP3)
2067 sdps (or SDPS)
2068 imap (or IMAP)
2069 apop (or APOP)
2070 kpop (or KPOP)
2071 Legal authentication types are 'any', 'password', 'kerberos', 'ker‐
2074 beros_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn' (only
2075 for POP3), 'ntlm', 'ssh', 'external' (only IMAP). The 'password' type
2076 specifies authentication by normal transmission of a password (the
2077 password may be plain text or subject to protocol-specific encryption
2078 as in CRAM-MD5); 'kerberos' tells fetchmail to try to get a Kerberos
2079 ticket at the start of each query instead, and send an arbitrary string
2080 as the password; and 'gssapi' tells fetchmail to use GSSAPI authentica‐
2081 tion. See the description of the 'auth' keyword for more.
2082 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
2084 authentication. These defaults may be overridden by later options.
2085 There are some global option statements: 'set logfile' followed by a
2087 string sets the same global specified by --logfile. A command-line
2088 --logfile option will override this. Note that --logfile is only effec‐
2089 tive if fetchmail detaches itself from the terminal and the logfile
2090 already exists before fetchmail is run, and it overrides --syslog in
2091 this case. Also, 'set daemon' sets the poll interval as --daemon does.
2092 This can be overridden by a command-line --daemon option; in particular
2093 --daemon 0 can be used to force foreground operation. The 'set postmas‐
2094 ter' statement sets the address to which multidrop mail defaults if
2095 there are no local matches. Finally, 'set syslog' sends log messages
2096 to syslogd(8).
2097
2100 Fetchmail crashing
2101 There are various ways in that fetchmail may "crash", i. e. stop opera‐
2102 tion suddenly and unexpectedly. A "crash" usually refers to an error
2103 condition that the software did not handle by itself. A well-known
2104 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
2105 just "segfault" for short. These can be caused by hardware or by soft‐
2106 ware problems. Software-induced segfaults can usually be reproduced
2107 easily and in the same place, whereas hardware-induced segfaults can go
2108 away if the computer is rebooted, or powered off for a few hours, and
2109 can happen in random locations even if you use the software the same
2110 way.
2111 For solving hardware-induced segfaults, find the faulty component and
2113 repair or replace it. The Sig11 FAQ ⟨http://www.bitwizard.nl/sig11/⟩
2114 may help you with details.
2115 For solving software-induced segfaults, the developers may need a
2117 "stack backtrace".
2118 Enabling fetchmail core dumps
2121 By default, fetchmail suppresses core dumps as these might contain
2122 passwords and other sensitive information. For debugging fetchmail
2123 crashes, obtaining a "stack backtrace" from a core dump is often the
2124 quickest way to solve the problem, and when posting your problem on a
2125 mailing list, the developers may ask you for a "backtrace".
2126 1. To get useful backtraces, fetchmail needs to be installed without
2128 getting stripped of its compilation symbols. Unfortunately, most
2129 binary packages that are installed are stripped, and core files from
2130 symbol-stripped programs are worthless. So you may need to recompile
2131 fetchmail. On many systems, you can type
2132 file `which fetchmail`
2134 to find out if fetchmail was symbol-stripped or not. If yours was
2136 unstripped, fine, proceed, if it was stripped, you need to recompile
2137 the source code first. You do not usually need to install fetchmail in
2138 order to debug it.
2139 2. The shell environment that starts fetchmail needs to enable core
2141 dumps. The key is the "maximum core (file) size" that can usually be
2142 configured with a tool named "limit" or "ulimit". See the documentation
2143 for your shell for details. In the popular bash shell, "ulimit -Sc
2144 unlimited" will allow the core dump.
2145 3. You need to tell fetchmail, too, to allow core dumps. To do this,
2147 run fetchmail with the -d0 -v options. It is often easier to also add
2148 --nosyslog -N as well.
2149 Finally, you need to reproduce the crash. You can just start fetchmail
2151 from the directory where you compiled it by typing ./fetchmail, so the
2152 complete command line will start with ./fetchmail -Nvd0 --nosyslog and
2153 perhaps list your other options.
2154 After the crash, run your debugger to obtain the core dump. The debug‐
2156 ger will often be GNU GDB, you can then type (adjust paths as neces‐
2157 sary) gdb ./fetchmail fetchmail.core and then, after GDB has started up
2158 and read all its files, type backtrace full, save the output (copy &
2159 paste will do, the backtrace will be read by a human) and then type
2160 quit to leave gdb. Note: on some systems, the core files have differ‐
2161 ent names, they might contain a number instead of the program name, or
2162 number and name, but it will usually have "core" as part of their name.
2163
2166 When trying to determine the originating address of a message, fetch‐
2167 mail looks through headers in the following order:
2168 Return-Path:
2170 Resent-Sender: (ignored if it doesn't contain an @ or !)
2171 Sender: (ignored if it doesn't contain an @ or !)
2172 Resent-From:
2173 From:
2174 Reply-To:
2175 Apparently-From:
2176 The originating address is used for logging, and to set the MAIL FROM
2178 address when forwarding to SMTP. This order is intended to cope grace‐
2179 fully with receiving mailing list messages in multidrop mode. The
2180 intent is that if a local address doesn't exist, the bounce message
2181 won't be returned blindly to the author or to the list itself, but
2182 rather to the list manager (which is less annoying).
2183 In multidrop mode, destination headers are processed as follows: First,
2185 fetchmail looks for the header specified by the 'envelope' option in
2186 order to determine the local recipient address. If the mail is
2187 addressed to more than one recipient, the Received line won't contain
2188 any information regarding recipient addresses.
2189 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2191 lines. If they exist, they should contain the final recipients and
2192 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
2193 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2194 looked for. (The presence of a Resent-To: is taken to imply that the
2195 person referred by the To: address has already received the original
2196 copy of the mail.)
2197
2200 Note that although there are password declarations in a good many of
2201 the examples below, this is mainly for illustrative purposes. We rec‐
2202 ommend stashing account/password pairs in your $HOME/.netrc file, where
2203 they can be used not just by fetchmail but by ftp(1) and other pro‐
2204 grams.
2205 The basic format is:
2207 poll SERVERNAME protocol PROTOCOL username NAME password PASS‐
2210 WORD
2211 Example:
2214 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2217 Or, using some abbreviations:
2220 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2223 Multiple servers may be listed:
2226 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2229 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2230 Here's the same version with more whitespace and some noise words:
2233 poll pop.provider.net proto pop3
2236 user "jsmith", with password secret1, is "jsmith" here;
2237 poll other.provider.net proto pop2:
2238 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2239 If you need to include whitespace in a parameter string or start the
2242 latter with a number, enclose the string in double quotes. Thus:
2243 poll mail.provider.net with proto pop3:
2246 user "jsmith" there has password "4u but u can't krak this"
2247 is jws here and wants mda "/bin/mail"
2248 You may have an initial server description headed by the keyword
2251 'defaults' instead of 'poll' followed by a name. Such a record is
2252 interpreted as defaults for all queries to use. It may be overwritten
2253 by individual server descriptions. So, you could write:
2254 defaults proto pop3
2257 user "jsmith"
2258 poll pop.provider.net
2259 pass "secret1"
2260 poll mail.provider.net
2261 user "jjsmith" there has password "secret2"
2262 It's possible to specify more than one user per server. The 'user'
2265 keyword leads off a user description, and every user specification in a
2266 multi-user entry must include it. Here's an example:
2267 poll pop.provider.net proto pop3 port 3111
2270 user "jsmith" with pass "secret1" is "smith" here
2271 user jones with pass "secret2" is "jjones" here keep
2272 This associates the local username 'smith' with the pop.provider.net
2275 username 'jsmith' and the local username 'jjones' with the
2276 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2277 server after download.
2278 Here's what a simple retrieval configuration for a multidrop mailbox
2281 looks like:
2282 poll pop.provider.net:
2285 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2286 This says that the mailbox of account 'maildrop' on the server is a
2289 multidrop box, and that messages in it should be parsed for the server
2290 user names 'golux', 'hurkle', and 'snark'. It further specifies that
2291 'golux' and 'snark' have the same name on the client as on the server,
2292 but mail for server user 'hurkle' should be delivered to client user
2293 'happy'.
2294 Note that fetchmail, until version 6.3.4, did NOT allow full
2297 user@domain specifications here, these would never match. Fetchmail
2298 6.3.5 and newer support user@domain specifications on the left-hand
2299 side of a user mapping.
2300 Here's an example of another kind of multidrop connection:
2303 poll pop.provider.net localdomains loonytoons.org toons.org
2306 envelope X-Envelope-To
2307 user maildrop with pass secret1 to * here
2308 This also says that the mailbox of account 'maildrop' on the server is
2311 a multidrop box. It tells fetchmail that any address in the loony‐
2312 toons.org or toons.org domains (including sub-domain addresses like
2313 'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2314 listener without modification. Be careful of mail loops if you do
2315 this!
2316 Here's an example configuration using ssh and the plugin option. The
2319 queries are made directly on the stdin and stdout of imapd via ssh.
2320 Note that in this setup, IMAP authentication can be skipped.
2321 poll mailhost.net with proto imap:
2324 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2325 user esr is esr here
2326
2329 Use the multiple-local-recipients feature with caution -- it can bite.
2330 All multidrop features are ineffective in ETRN and ODMR modes.
2331 Also, note that in multidrop mode duplicate mails are suppressed. A
2333 piece of mail is considered duplicate if it has the same message-ID as
2334 the message immediately preceding and more than one addressee. Such
2335 runs of messages may be generated when copies of a message addressed to
2336 multiple users are delivered to a multidrop box.
2337 Header vs. Envelope addresses
2340 The fundamental problem is that by having your mailserver toss several
2341 peoples' mail in a single maildrop box, you may have thrown away poten‐
2342 tially vital information about who each piece of mail was actually
2343 addressed to (the 'envelope address', as opposed to the header
2344 addresses in the RFC822 To/Cc headers - the Bcc is not available at the
2345 receiving end). This 'envelope address' is the address you need in
2346 order to reroute mail properly.
2347 Sometimes fetchmail can deduce the envelope address. If the mailserver
2349 MTA is sendmail and the item of mail had just one recipient, the MTA
2350 will have written a 'by/for' clause that gives the envelope addressee
2351 into its Received header. But this doesn't work reliably for other
2352 MTAs, nor if there is more than one recipient. By default, fetchmail
2353 looks for envelope addresses in these lines; you can restore this
2354 default with -E "Received" or 'envelope Received'.
2355 As a better alternative, some SMTP listeners and/or mail servers insert
2357 a header in each message containing a copy of the envelope addresses.
2358 This header (when it exists) is often 'X-Original-To', 'Delivered-To'
2359 or 'X-Envelope-To'. Fetchmail's assumption about this can be changed
2360 with the -E or 'envelope' option. Note that writing an envelope header
2361 of this kind exposes the names of recipients (including blind-copy
2362 recipients) to all receivers of the messages, so the upstream must
2363 store one copy of the message per recipient to avoid becoming a privacy
2364 problem.
2365 Postfix, since version 2.0, writes an X-Original-To: header which con‐
2367 tains a copy of the envelope as it was received.
2368 Qmail and Postfix generally write a 'Delivered-To' header upon deliver‐
2370 ing the message to the mail spool and use it to avoid mail loops.
2371 Qmail virtual domains however will prefix the user name with a string
2372 that normally matches the user's domain. To remove this prefix you can
2373 use the -Q or 'qvirtual' option.
2374 Sometimes, unfortunately, neither of these methods works. That is the
2376 point when you should contact your ISP and ask them to provide such an
2377 envelope header, and you should not use multidrop in this situation.
2378 When they all fail, fetchmail must fall back on the contents of To/Cc
2379 headers (Bcc headers are not available - see below) to try to determine
2380 recipient addressees -- and these are unreliable. In particular, mail‐
2381 ing-list software often ships mail with only the list broadcast address
2382 in the To header.
2383 Note that a future version of fetchmail may remove To/Cc parsing!
2385 When fetchmail cannot deduce a recipient address that is local, and the
2387 intended recipient address was anyone other than fetchmail's invoking
2388 user, mail will get lost. This is what makes the multidrop feature
2389 risky without proper envelope information.
2390 A related problem is that when you blind-copy a mail message, the Bcc
2392 information is carried only as envelope address (it's removed from the
2393 headers by the sending mail server, so fetchmail can see it only if
2394 there is an X-Envelope-To header). Thus, blind-copying to someone who
2395 gets mail over a fetchmail multidrop link will fail unless the the
2396 mailserver host routinely writes X-Envelope-To or an equivalent header
2397 into messages in your maildrop.
2398 In conclusion, mailing lists and Bcc'd mail can only work if the server
2400 you're fetching from
2401 (1) stores one copy of the message per recipient in your domain and
2403 (2) records the envelope information in a special header (X-Origi‐
2405 nal-To, Delivered-To, X-Envelope-To).
2406 Good Ways To Use Multidrop Mailboxes
2409 Multiple local names can be used to administer a mailing list from the
2410 client side of a fetchmail collection. Suppose your name is 'esr', and
2411 you want to both pick up your own mail and maintain a mailing list
2412 called (say) "fetchmail-friends", and you want to keep the alias list
2413 on your client machine.
2414 On your server, you can alias 'fetchmail-friends' to 'esr'; then, in
2416 your .fetchmailrc, declare 'to esr fetchmail-friends here'. Then, when
2417 mail including 'fetchmail-friends' as a local address gets fetched, the
2418 list name will be appended to the list of recipients your SMTP listener
2419 sees. Therefore it will undergo alias expansion locally. Be sure to
2420 include 'esr' in the local alias expansion of fetchmail-friends, or
2421 you'll never see mail sent only to the list. Also be sure that your
2422 listener has the "me-too" option set (sendmail's -oXm command-line
2423 option or OXm declaration) so your name isn't removed from alias expan‐
2424 sions in messages you send.
2425 This trick is not without its problems, however. You'll begin to see
2427 this when a message comes in that is addressed only to a mailing list
2428 you do not have declared as a local name. Each such message will fea‐
2429 ture an 'X-Fetchmail-Warning' header which is generated because fetch‐
2430 mail cannot find a valid local name in the recipient addresses. Such
2431 messages default (as was described above) to being sent to the local
2432 user running fetchmail, but the program has no way to know that that's
2433 actually the right thing.
2434 Bad Ways To Abuse Multidrop Mailboxes
2437 Multidrop mailboxes and fetchmail serving multiple users in daemon mode
2438 do not mix. The problem, again, is mail from mailing lists, which typ‐
2439 ically does not have an individual recipient address on it. Unless
2440 fetchmail can deduce an envelope address, such mail will only go to the
2441 account running fetchmail (probably root). Also, blind-copied users
2442 are very likely never to see their mail at all.
2443 If you're tempted to use fetchmail to retrieve mail for multiple users
2445 from a single mail drop via POP or IMAP, think again (and reread the
2446 section on header and envelope addresses above). It would be smarter
2447 to just let the mail sit in the mailserver's queue and use fetchmail's
2448 ETRN or ODMR modes to trigger SMTP sends periodically (of course, this
2449 means you have to poll more frequently than the mailserver's expiry
2450 period). If you can't arrange this, try setting up a UUCP feed.
2451 If you absolutely must use multidrop for this purpose, make sure your
2453 mailserver writes an envelope-address header that fetchmail can see.
2454 Otherwise you will lose mail and it will come back to haunt you.
2455 Speeding Up Multidrop Checking
2458 Normally, when multiple users are declared fetchmail extracts recipient
2459 addresses as described above and checks each host part with DNS to see
2460 if it's an alias of the mailserver. If so, the name mappings described
2461 in the "to ... here" declaration are done and the mail locally deliv‐
2462 ered.
2463 This is a convenient but also slow method. To speed it up, pre-declare
2465 mailserver aliases with 'aka'; these are checked before DNS lookups are
2466 done. If you're certain your aka list contains all DNS aliases of the
2467 mailserver (and all MX names pointing at it - note this may change in a
2468 future version) you can declare 'no dns' to suppress DNS lookups
2469 entirely and only match against the aka list.
2470
2473 Support for socks4/5 is a compile time configuration option. Once com‐
2474 piled in, fetchmail will always use the socks libraries and configura‐
2475 tion on your system, there are no run-time switches in fetchmail - but
2476 you can still configure SOCKS: you can specify which SOCKS configura‐
2477 tion file is used in the SOCKS_CONF environment variable.
2478 For instance, if you wanted to bypass the SOCKS proxy altogether and
2480 have fetchmail connect directly, you could just pass
2481 SOCKS_CONF=/dev/null in the environment, for example (add your usual
2482 command line options - if any - to the end of this line):
2483 env SOCKS_CONF=/dev/null fetchmail
2485
2488 To facilitate the use of fetchmail in shell scripts, an exit status
2489 code is returned to give an indication of what occurred during a given
2490 connection.
2491 The exit codes returned by fetchmail are as follows:
2493 0 One or more messages were successfully retrieved (or, if the -c
2495 option was selected, were found waiting but not retrieved).
2496 1 There was no mail awaiting retrieval. (There may have been old
2498 mail still on the server but not selected for retrieval.) If you
2499 do not want "no mail" to be an error condition (for instance,
2500 for cron jobs), use a POSIX-compliant shell and add
2501 || [ $? -eq 1 ]
2503 to the end of the fetchmail command line, note that this leaves
2505 0 untouched, maps 1 to 0, and maps all other codes to 1. See
2506 also item #C8 in the FAQ.
2507 2 An error was encountered when attempting to open a socket to
2509 retrieve mail. If you don't know what a socket is, don't worry
2510 about it -- just treat this as an 'unrecoverable error'. This
2511 error can also be because a protocol fetchmail wants to use is
2512 not listed in /etc/services.
2513 3 The user authentication step failed. This usually means that a
2515 bad user-id, password, or APOP id was specified. Or it may mean
2516 that you tried to run fetchmail under circumstances where it did
2517 not have standard input attached to a terminal and could not
2518 prompt for a missing password.
2519 4 Some sort of fatal protocol error was detected.
2521 5 There was a syntax error in the arguments to fetchmail, or a
2523 pre- or post-connect command failed.
2524 6 The run control file had bad permissions.
2526 7 There was an error condition reported by the server. Can also
2528 fire if fetchmail timed out while waiting for the server.
2529 8 Client-side exclusion error. This means fetchmail either found
2531 another copy of itself already running, or failed in such a way
2532 that it isn't sure whether another copy is running.
2533 9 The user authentication step failed because the server responded
2535 "lock busy". Try again after a brief pause! This error is not
2536 implemented for all protocols, nor for all servers. If not
2537 implemented for your server, "3" will be returned instead, see
2538 above. May be returned when talking to qpopper or other servers
2539 that can respond with "lock busy" or some similar text contain‐
2540 ing the word "lock".
2541 10 The fetchmail run failed while trying to do an SMTP port open or
2543 transaction.
2544 11 Fatal DNS error. Fetchmail encountered an error while perform‐
2546 ing a DNS lookup at startup and could not proceed.
2547 12 BSMTP batch file could not be opened.
2549 13 Poll terminated by a fetch limit (see the --fetchlimit option).
2551 14 Server busy indication.
2553 23 Internal error. You should see a message on standard error with
2555 details.
2556 24 - 26, 28, 29
2558 These are internal codes and should not appear externally.
2559 When fetchmail queries more than one host, return status is 0 if any
2561 query successfully retrieved mail. Otherwise the returned error status
2562 is that of the last host queried.
2563
2566 ~/.fetchmailrc
2567 default run control file
2568 ~/.fetchids
2570 default location of file recording last message UIDs seen per
2571 host.
2572 ~/.fetchmail.pid
2574 lock file to help prevent concurrent runs (non-root mode).
2575 ~/.netrc
2577 your FTP run control file, which (if present) will be searched for
2578 passwords as a last resort before prompting for one interactively.
2579 /var/run/fetchmail.pid
2581 lock file to help prevent concurrent runs (root mode, Linux sys‐
2582 tems).
2583 /etc/fetchmail.pid
2585 lock file to help prevent concurrent runs (root mode, systems
2586 without /var/run).
2587
2590 FETCHMAILHOME
2591 If this environment variable is set to a valid and existing
2592 directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
2593 (the dot is missing in this case), $FETCHMAILHOME/.fetchids and
2594 $FETCHMAILHOME/.fetchmail.pid rather than from the user's home
2595 directory. The .netrc file is always looked for in the the
2596 invoking user's home directory regardless of FETCHMAILHOME's
2597 setting.
2598 FETCHMAILUSER
2601 If this environment variable is set, it is used as the name of
2602 the calling user (default local name) for purposes such as mail‐
2603 ing error notifications. Otherwise, if either the LOGNAME or
2604 USER variable is correctly set (e.g. the corresponding UID
2605 matches the session user ID) then that name is used as the
2606 default local name. Otherwise getpwuid(3) must be able to
2607 retrieve a password entry for the session ID (this elaborate
2608 logic is designed to handle the case of multiple names per
2609 userid gracefully).
2610 FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE
2613 (since v6.3.22): If this environment variable is set and not
2614 empty, fetchmail will disable a countermeasure against an SSL
2615 CBC IV attack (by setting SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS).
2616 This is a security risk, but may be necessary for connecting to
2617 certain non-standards-conforming servers. See fetchmail's NEWS
2618 file and fetchmail-SA-2012-01.txt for details. Earlier fetch‐
2619 mail versions (v6.3.21 and older) used to disable this counter‐
2620 measure, but v6.3.22 no longer does that as a safety precaution.
2621 FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS
2624 (since v6.3.17): If this environment variable is set and not
2625 empty, fetchmail will always load the default X.509 trusted cer‐
2626 tificate locations for SSL/TLS CA certificates, even if
2627 --sslcertfile and --sslcertpath are given. The latter locations
2628 take precedence over the system default locations. This is use‐
2629 ful in case there are broken certificates in the system directo‐
2630 ries and the user has no administrator privileges to remedy the
2631 problem.
2632 HOME_ETC
2635 If the HOME_ETC variable is set, fetchmail will read
2636 $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.
2637 If HOME_ETC and FETCHMAILHOME are both set, HOME_ETC will be
2639 ignored.
2640 SOCKS_CONF
2643 (only if SOCKS support is compiled in) this variable is used by
2644 the socks library to find out which configuration file it should
2645 read. Set this to /dev/null to bypass the SOCKS proxy.
2646
2649 If a fetchmail daemon is running as root, SIGUSR1 wakes it up from its
2650 sleep phase and forces a poll of all non-skipped servers. For compati‐
2651 bility reasons, SIGHUP can also be used in 6.3.X but may not be avail‐
2652 able in future fetchmail versions.
2653 If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake
2655 it (this is so SIGHUP due to logout can retain the default action of
2656 killing it).
2657 Running fetchmail in foreground while a background fetchmail is running
2659 will do whichever of these is appropriate to wake it up.
2660
2663 Please check the NEWS file that shipped with fetchmail for more known
2664 bugs than those listed here.
2665 Fetchmail cannot handle user names that contain blanks after a "@"
2667 character, for instance "demonstr@ti on". These are rather uncommon and
2668 only hurt when using UID-based --keep setups, so the 6.3.X versions of
2669 fetchmail won't be fixed.
2670 Fetchmail cannot handle configurations where you have multiple accounts
2672 that use the same server name and the same login. Any user@server com‐
2673 bination must be unique.
2674 The assumptions that the DNS and in particular the checkalias options
2676 make are not often sustainable. For instance, it has become uncommon
2677 for an MX server to be a POP3 or IMAP server at the same time. There‐
2678 fore the MX lookups may go away in a future release.
2679 The mda and plugin options interact badly. In order to collect error
2681 status from the MDA, fetchmail has to change its normal signal handling
2682 so that dead plugin processes don't get reaped until the end of the
2683 poll cycle. This can cause resource starvation if too many zombies
2684 accumulate. So either don't deliver to a MDA using plugins or risk
2685 being overrun by an army of undead.
2686 The --interface option does not support IPv6 and it is doubtful if it
2688 ever will, since there is no portable way to query interface IPv6
2689 addresses.
2690 The RFC822 address parser used in multidrop mode chokes on some
2692 @-addresses that are technically legal but bizarre. Strange uses of
2693 quoting and embedded comments are likely to confuse it.
2694 In a message with multiple envelope headers, only the last one pro‐
2696 cessed will be visible to fetchmail.
2697 Use of some of these protocols requires that the program send unen‐
2699 crypted passwords over the TCP/IP connection to the mailserver. This
2700 creates a risk that name/password pairs might be snaffled with a packet
2701 sniffer or more sophisticated monitoring software. Under Linux and
2702 FreeBSD, the --interface option can be used to restrict polling to
2703 availability of a specific interface device with a specific local or
2704 remote IP address, but snooping is still possible if (a) either host
2705 has a network device that can be opened in promiscuous mode, or (b) the
2706 intervening network link can be tapped. We recommend the use of ssh(1)
2707 tunnelling to not only shroud your passwords but encrypt the entire
2708 conversation.
2709 Use of the %F or %T escapes in an mda option could open a security
2711 hole, because they pass text manipulable by an attacker to a shell com‐
2712 mand. Potential shell characters are replaced by '_' before execution.
2713 The hole is further reduced by the fact that fetchmail temporarily dis‐
2714 cards any suid privileges it may have while running the MDA. For maxi‐
2715 mum safety, however, don't use an mda command containing %F or %T when
2716 fetchmail is run from the root account itself.
2717 Fetchmail's method of sending bounces due to errors or spam-blocking
2719 and spam bounces requires that port 25 of localhost be available for
2720 sending mail via SMTP.
2721 If you modify ~/.fetchmailrc while a background instance is running and
2723 break the syntax, the background instance will die silently. Unfortu‐
2724 nately, it can't die noisily because we don't yet know whether syslog
2725 should be enabled. On some systems, fetchmail dies quietly even if
2726 there is no syntax error; this seems to have something to do with buggy
2727 terminal ioctl code in the kernel.
2728 The -f - option (reading a configuration from stdin) is incompatible
2730 with the plugin option.
2731 The 'principal' option only handles Kerberos IV, not V.
2733 Interactively entered passwords are truncated after 63 characters. If
2735 you really need to use a longer password, you will have to use a con‐
2736 figuration file.
2737 A backslash as the last character of a configuration file will be
2739 flagged as a syntax error rather than ignored.
2740 The BSMTP error handling is virtually nonexistent and may leave broken
2742 messages behind.
2743 Send comments, bug reports, gripes, and the like to the fetchmail-devel
2745 list ⟨fetchmail-devel@lists.berlios.de⟩
2746 An HTML FAQ ⟨http://fetchmail.berlios.de/fetchmail-FAQ.html⟩ is avail‐
2749 able at the fetchmail home page, it should also accompany your instal‐
2750 lation.
2751
2754 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2755 major assistance from Sunil Shetye (for code) and Rob MacGregor (for
2756 the mailing lists).
2757 Most of the code is from Eric S. Raymond ⟨esr@snark.thyrsus.com⟩ . Too
2759 many other people to name here have contributed code and patches.
2760 This program is descended from and replaces popclient, by Carl Harris
2762 ⟨ceharris@mal.com⟩ ; the internals have become quite different, but
2763 some of its interface design is directly traceable to that ancestral
2764 program.
2765 This manual page has been improved by Matthias Andree, R. Hannes Bein‐
2767 ert, and Héctor García.
2768
2771 README, README.SSL, README.SSL-SERVER, The Fetchmail FAQ ⟨http://
2772 www.fetchmail.info/fetchmail-FAQ.html⟩, mutt(1), elm(1), mail(1), send‐
2773 mail(8), popd(8), imapd(8), netrc(5).
2774 The fetchmail home page. ⟨http://fetchmail.berlios.de/⟩
2777 The maildrop home page. ⟨http://www.courier-mta.org/maildrop/⟩
2780
2783 Note that this list is just a collection of references and not a state‐
2784 ment as to the actual protocol conformance or requirements in fetch‐
2785 mail.
2786 SMTP/ESMTP:
2788 RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC
2789 1985, RFC 2554.
2790 mail:
2792 RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
2793 POP2:
2795 RFC 937
2796 POP3:
2798 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC
2799 1957, RFC 2195, RFC 2449.
2800 APOP:
2802 RFC 1939.
2803 RPOP:
2805 RFC 1081, RFC 1225.
2806 IMAP2/IMAP2BIS:
2808 RFC 1176, RFC 1732.
2809 IMAP4/IMAP4rev1:
2811 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC
2812 2177, RFC 2683.
2813 ETRN:
2815 RFC 1985.
2816 ODMR/ATRN:
2818 RFC 2645.
2819 OTP: RFC 1938.
2821 LMTP:
2823 RFC 2033.
2824 GSSAPI:
2826 RFC 1508, RFC 1734, Generic Security Service Application Program
2827 Interface (GSSAPI)/Kerberos/Simple Authentication and Security
2828 Layer (SASL) Service Names ⟨http://www.iana.org/assignments/
2829 gssapi-service-names/⟩.
2830 TLS: RFC 2595.
2832fetchmail fetchmail 6.3.24 fetchmail(1)