1fetchmail(1) fetchmail reference manual fetchmail(1)
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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 -V | --version
157 Displays the version information for your copy of fetchmail. No
158 mail fetch is performed. Instead, for each server specified,
159 all the option information that would be computed if fetchmail
160 were connecting to that server is displayed. Any non-printables
161 in passwords or other string names are shown as backslashed C-
162 like escape sequences. This option is useful for verifying that
163 your options are set the way you want them.
164 -c | --check
166 Return a status code to indicate whether there is mail waiting,
167 without actually fetching or deleting mail (see EXIT CODES
168 below). This option turns off daemon mode (in which it would be
169 useless). It doesn't play well with queries to multiple sites,
170 and doesn't work with ETRN or ODMR. It will return a false pos‐
171 itive if you leave read but undeleted mail in your server mail‐
172 box and your fetch protocol can't tell kept messages from new
173 ones. This means it will work with IMAP, not work with POP2,
174 and may occasionally flake out under POP3.
175 -s | --silent
177 Silent mode. Suppresses all progress/status messages that are
178 normally echoed to standard output during a fetch (but does not
179 suppress actual error messages). The --verbose option overrides
180 this.
181 -v | --verbose
183 Verbose mode. All control messages passed between fetchmail and
184 the mailserver are echoed to stdout. Overrides --silent. Dou‐
185 bling this option (-v -v) causes extra diagnostic information to
186 be printed.
187 --nosoftbounce
189 (since v6.3.10, Keyword: set no softbounce, since v6.3.10)
190 Hard bounce mode. All permanent delivery errors cause messages
191 to be deleted from the upstream server, see "no softbounce"
192 below.
193 --softbounce
195 (since v6.3.10, Keyword: set softbounce, since v6.3.10)
196 Soft bounce mode. All permanent delivery errors cause messages
197 to be left on the upstream server if the protocol supports that.
198 Default to match historic fetchmail documentation, to be changed
199 to hard bounce mode in the next fetchmail release.
200 Disposal Options
202 -a | --all | (since v6.3.3) --fetchall
203 (Keyword: fetchall, since v3.0)
204 Retrieve both old (seen) and new messages from the mailserver.
205 The default is to fetch only messages the server has not marked
206 seen. Under POP3, this option also forces the use of RETR
207 rather than TOP. Note that POP2 retrieval behaves as though
208 --all is always on (see RETRIEVAL FAILURE MODES below) and this
209 option does not work with ETRN or ODMR. While the -a and --all
210 command-line and fetchall rcfile options have been supported for
211 a long time, the --fetchall command-line option was added in
212 v6.3.3.
213 -k | --keep
215 (Keyword: keep)
216 Keep retrieved messages on the remote mailserver. Normally,
217 messages are deleted from the folder on the mailserver after
218 they have been retrieved. Specifying the keep option causes
219 retrieved messages to remain in your folder on the mailserver.
220 This option does not work with ETRN or ODMR. If used with POP3,
221 it is recommended to also specify the --uidl option or uidl key‐
222 word.
223 -K | --nokeep
225 (Keyword: nokeep)
226 Delete retrieved messages from the remote mailserver. This
227 option forces retrieved mail to be deleted. It may be useful if
228 you have specified a default of keep in your .fetchmailrc. This
229 option is forced on with ETRN and ODMR.
230 -F | --flush
232 (Keyword: flush)
233 POP3/IMAP only. This is a dangerous option and can cause mail
234 loss when used improperly. It deletes old (seen) messages from
235 the mailserver before retrieving new messages. Warning: This
236 can cause mail loss if you check your mail with other clients
237 than fetchmail, and cause fetchmail to delete a message it had
238 never fetched before. It can also cause mail loss if the mail
239 server marks the message seen after retrieval (IMAP2 servers).
240 You should probably not use this option in your configuration
241 file. If you use it with POP3, you must use the 'uidl' option.
242 What you probably want is the default setting: if you don't
243 specify '-k', then fetchmail will automatically delete messages
244 after successful delivery.
245 --limitflush
247 POP3/IMAP only, since version 6.3.0. Delete oversized messages
248 from the mailserver before retrieving new messages. The size
249 limit should be separately specified with the --limit option.
250 This option does not work with ETRN or ODMR.
251 Protocol and Query Options
253 -p <proto> | --proto <proto> | --protocol <proto>
254 (Keyword: proto[col])
255 Specify the protocol to use when communicating with the remote
256 mailserver. If no protocol is specified, the default is AUTO.
257 proto may be one of the following:
258 AUTO Tries IMAP, POP3, and POP2 (skipping any of these for
260 which support has not been compiled in).
261 POP2 Post Office Protocol 2 (legacy, to be removed from future
263 release)
264 POP3 Post Office Protocol 3
266 APOP Use POP3 with old-fashioned MD5-challenge authentication.
268 Considered not resistant to man-in-the-middle attacks.
269 RPOP Use POP3 with RPOP authentication.
271 KPOP Use POP3 with Kerberos V4 authentication on port 1109.
273 SDPS Use POP3 with Demon Internet's SDPS extensions.
275 IMAP IMAP2bis, IMAP4, or IMAP4rev1 (fetchmail automatically
277 detects their capabilities).
278 ETRN Use the ESMTP ETRN option.
280 ODMR Use the the On-Demand Mail Relay ESMTP profile.
282 All these alternatives work in basically the same way (communicating
284 with standard server daemons to fetch mail already delivered to a mail‐
285 box on the server) except ETRN and ODMR. The ETRN mode allows you to
286 ask a compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
287 higher) to immediately open a sender-SMTP connection to your client
288 machine and begin forwarding any items addressed to your client machine
289 in the server's queue of undelivered mail. The ODMR mode requires an
290 ODMR-capable server and works similarly to ETRN, except that it does
291 not require the client machine to have a static DNS.
292 -U | --uidl
294 (Keyword: uidl)
295 Force UIDL use (effective only with POP3). Force client-side
296 tracking of 'newness' of messages (UIDL stands for "unique ID
297 listing" and is described in RFC1939). Use with 'keep' to use a
298 mailbox as a baby news drop for a group of users. The fact that
299 seen messages are skipped is logged, unless error logging is
300 done through syslog while running in daemon mode. Note that
301 fetchmail may automatically enable this option depending on
302 upstream server capabilities. Note also that this option may be
303 removed and forced enabled in a future fetchmail version. See
304 also: --idfile.
305 --idle (since 6.3.3)
307 (Keyword: idle, since before 6.0.0)
308 Enable IDLE use (effective only with IMAP). Note that this works
309 with only one folder at a given time. While the idle rcfile
310 keyword had been supported for a long time, the --idle command-
311 line option was added in version 6.3.3. IDLE use means that
312 fetchmail tells the IMAP server to send notice of new messages,
313 so they can be retrieved sooner than would be possible with reg‐
314 ular polls.
315 -P <portnumber> | --service <servicename>
317 (Keyword: service) Since version 6.3.0.
318 The service option permits you to specify a service name to con‐
319 nect to. You can specify a decimal port number here, if your
320 services database lacks the required service-port assignments.
321 See the FAQ item R12 and the --ssl documentation for details.
322 This replaces the older --port option.
323 --port <portnumber>
325 (Keyword: port)
326 Obsolete version of --service that does not take service names.
327 Note: this option may be removed from a future version.
328 --principal <principal>
330 (Keyword: principal)
331 The principal option permits you to specify a service principal
332 for mutual authentication. This is applicable to POP3 or IMAP
333 with Kerberos authentication.
334 -t <seconds> | --timeout <seconds>
336 (Keyword: timeout)
337 The timeout option allows you to set a server-nonresponse time‐
338 out in seconds. If a mailserver does not send a greeting mes‐
339 sage or respond to commands for the given number of seconds,
340 fetchmail will drop the connection to it. Without such a time‐
341 out fetchmail might hang until the TCP connection times out,
342 trying to fetch mail from a down host, which may be very long.
343 This would be particularly annoying for a fetchmail running in
344 the background. There is a default timeout which fetchmail -V
345 will report. If a given connection receives too many timeouts
346 in succession, fetchmail will consider it wedged and stop retry‐
347 ing. The calling user will be notified by email if this hap‐
348 pens.
349 Beginning with fetchmail 6.3.10, the SMTP client uses the recom‐
351 mended minimum timeouts from RFC-5321 while waiting for the
352 SMTP/LMTP server it is talking to. You can raise the timeouts
353 even more, but you cannot shorten it. This is to avoid a painful
354 situation where fetchmail has been configured with a short time‐
355 out (a minute or less), ships a long message (many MBytes) to
356 the local MTA, which then takes longer than timeout to respond
357 "OK", which it eventually will; that would mean the mail gets
358 delivered properly, but fetchmail cannot notice it and will thus
359 refetch this big message over and over again.
360 --plugin <command>
362 (Keyword: plugin)
363 The plugin option allows you to use an external program to
364 establish the TCP connection. This is useful if you want to use
365 ssh, or need some special firewalling setup. The program will
366 be looked up in $PATH and can optionally be passed the hostname
367 and port as arguments using "%h" and "%p" respectively (note
368 that the interpolation logic is rather primitive, and these
369 tokens must be bounded by whitespace or beginning of string or
370 end of string). Fetchmail will write to the plugin's stdin and
371 read from the plugin's stdout.
372 --plugout <command>
374 (Keyword: plugout)
375 Identical to the plugin option above, but this one is used for
376 the SMTP connections.
377 -r <name> | --folder <name>
379 (Keyword: folder[s])
380 Causes a specified non-default mail folder on the mailserver (or
381 comma-separated list of folders) to be retrieved. The syntax of
382 the folder name is server-dependent. This option is not avail‐
383 able under POP3, ETRN, or ODMR.
384 --tracepolls
386 (Keyword: tracepolls)
387 Tell fetchmail to poll trace information in the form 'polling
388 account %s' and 'folder %s' to the Received line it generates,
389 where the %s parts are replaced by the user's remote name, the
390 poll label, and the folder (mailbox) where available (the
391 Received header also normally includes the server's true name).
392 This can be used to facilitate mail filtering based on the
393 account it is being received from. The folder information is
394 written only since version 6.3.4.
395 --ssl (Keyword: ssl)
397 Causes the connection to the mail server to be encrypted via
398 SSL. Connect to the server using the specified base protocol
399 over a connection secured by SSL. This option defeats oppor‐
400 tunistic starttls negotiation. It is highly recommended to use
401 --sslproto 'SSL3' --sslcertck to validate the certificates pre‐
402 sented by the server and defeat the obsolete SSLv2 negotiation.
403 More information is available in the README.SSL file that ships
404 with fetchmail.
405 Note that fetchmail may still try to negotiate SSL through
407 starttls even if this option is omitted. You can use the --ssl‐
408 proto option to defeat this behavior or tell fetchmail to nego‐
409 tiate a particular SSL protocol.
410 If no port is specified, the connection is attempted to the well
412 known port of the SSL version of the base protocol. This is
413 generally a different port than the port used by the base proto‐
414 col. For IMAP, this is port 143 for the clear protocol and port
415 993 for the SSL secured protocol, for POP3, it is port 110 for
416 the clear text and port 995 for the encrypted variant.
417 If your system lacks the corresponding entries from /etc/ser‐
419 vices, see the --service option and specify the numeric port
420 number as given in the previous paragraph (unless your ISP had
421 directed you to different ports, which is uncommon however).
422 --sslcert <name>
424 (Keyword: sslcert)
425 For certificate-based client authentication. Some SSL encrypted
426 servers require client side keys and certificates for authenti‐
427 cation. In most cases, this is optional. This specifies the
428 location of the public key certificate to be presented to the
429 server at the time the SSL session is established. It is not
430 required (but may be provided) if the server does not require
431 it. It may be the same file as the private key (combined key
432 and certificate file) but this is not recommended. Also see
433 --sslkey below.
434 NOTE: If you use client authentication, the user name is fetched
436 from the certificate's CommonName and overrides the name set
437 with --user.
438 --sslkey <name>
440 (Keyword: sslkey)
441 Specifies the file name of the client side private SSL key.
442 Some SSL encrypted servers require client side keys and certifi‐
443 cates for authentication. In most cases, this is optional.
444 This specifies the location of the private key used to sign
445 transactions with the server at the time the SSL session is
446 established. It is not required (but may be provided) if the
447 server does not require it. It may be the same file as the pub‐
448 lic key (combined key and certificate file) but this is not rec‐
449 ommended.
450 If a password is required to unlock the key, it will be prompted
452 for at the time just prior to establishing the session to the
453 server. This can cause some complications in daemon mode.
454 Also see --sslcert above.
456 --sslproto <name>
458 (Keyword: sslproto)
459 Forces an SSL/TLS protocol. Possible values are '', 'SSL2',
460 'SSL23', (use of these two values is discouraged and should only
461 be used as a last resort) 'SSL3', and 'TLS1'. The default be‐
462 haviour if this option is unset is: for connections without
463 --ssl, use 'TLS1' that fetchmail will opportunistically try
464 STARTTLS negotiation with TLS1. You can configure this option
465 explicitly if the default handshake (TLS1 if --ssl is not used,
466 does not work for your server.
467 Use this option with 'TLS1' value to enforce a STARTTLS connec‐
469 tion. In this mode, it is highly recommended to also use
470 --sslcertck (see below).
471 To defeat opportunistic TLSv1 negotiation when the server adver‐
473 tises STARTTLS or STLS, use ''. This option, even if the argu‐
474 ment is the empty string, will also suppress the diagnostic
475 'SERVER: opportunistic upgrade to TLS.' message in verbose mode.
476 The default is to try appropriate protocols depending on con‐
477 text.
478 --sslcertck
480 (Keyword: sslcertck)
481 Causes fetchmail to strictly check the server certificate
482 against a set of local trusted certificates (see the sslcertfile
483 and sslcertpath options). If the server certificate cannot be
484 obtained or is not signed by one of the trusted ones (directly
485 or indirectly), the SSL connection will fail, regardless of the
486 sslfingerprint option.
487 Note that CRL (certificate revocation lists) are only supported
489 in OpenSSL 0.9.7 and newer! Your system clock should also be
490 reasonably accurate when using this option.
491 Note that this optional behavior may become default behavior in
493 future fetchmail versions.
494 --sslcertfile <file>
496 (Keyword: sslcertfile, since v6.3.17)
497 Sets the file fetchmail uses to look up local certificates. The
498 default is empty. This can be given in addition to --sslcert‐
499 path below, and certificates specified in --sslcertfile will be
500 processed before those in --sslcertpath. The option can be used
501 in addition to --sslcertpath.
502 The file is a text file. It contains the concatenation of
504 trusted CA certificates in PEM format.
505 Note that using this option will suppress loading the default
507 SSL trusted CA certificates file unless you set the environment
508 variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
509 value.
510 --sslcertpath <directory>
512 (Keyword: sslcertpath)
513 Sets the directory fetchmail uses to look up local certificates.
514 The default is your OpenSSL default directory. The directory
515 must be hashed the way OpenSSL expects it - every time you add
516 or modify a certificate in the directory, you need to use the
517 c_rehash tool (which comes with OpenSSL in the tools/ subdirec‐
518 tory). Also, after OpenSSL upgrades, you may need to run
519 c_rehash; particularly when upgrading from 0.9.X to 1.0.0.
520 This can be given in addition to --sslcertfile above, which see
522 for precedence rules.
523 Note that using this option will suppress adding the default SSL
525 trusted CA certificates directory unless you set the environment
526 variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
527 value.
528 --sslcommonname <common name>
530 (Keyword: sslcommonname; since v6.3.9)
531 Use of this option is discouraged. Before using it, contact the
532 administrator of your upstream server and ask for a proper SSL
533 certificate to be used. If that cannot be attained, this option
534 can be used to specify the name (CommonName) that fetchmail
535 expects on the server certificate. A correctly configured
536 server will have this set to the hostname by which it is
537 reached, and by default fetchmail will expect as much. Use this
538 option when the CommonName is set to some other value, to avoid
539 the "Server CommonName mismatch" warning, and only if the
540 upstream server can't be made to use proper certificates.
541 --sslfingerprint <fingerprint>
543 (Keyword: sslfingerprint)
544 Specify the fingerprint of the server key (an MD5 hash of the
545 key) in hexadecimal notation with colons separating groups of
546 two digits. The letter hex digits must be in upper case. This is
547 the default format OpenSSL uses, and the one fetchmail uses to
548 report the fingerprint when an SSL connection is established.
549 When this is specified, fetchmail will compare the server key
550 fingerprint with the given one, and the connection will fail if
551 they do not match regardless of the sslcertck setting. The con‐
552 nection will also fail if fetchmail cannot obtain an SSL cer‐
553 tificate from the server. This can be used to prevent man-in-
554 the-middle attacks, but the finger print from the server needs
555 to be obtained or verified over a secure channel, and certainly
556 not over the same Internet connection that fetchmail would use.
557 Using this option will prevent printing certificate verification
559 errors as long as --sslcertck is unset.
560 To obtain the fingerprint of a certificate stored in the file
562 cert.pem, try:
563 openssl x509 -in cert.pem -noout -md5 -fingerprint
565 For details, see x509(1ssl).
567 Delivery Control Options
569 -S <hosts> | --smtphost <hosts>
570 (Keyword: smtp[host])
571 Specify a hunt list of hosts to forward mail to (one or more
572 hostnames, comma-separated). Hosts are tried in list order; the
573 first one that is up becomes the forwarding target for the cur‐
574 rent run. If this option is not specified, 'localhost' is used
575 as the default. Each hostname may have a port number following
576 the host name. The port number is separated from the host name
577 by a slash; the default port is "smtp". If you specify an abso‐
578 lute path name (beginning with a /), it will be interpreted as
579 the name of a UNIX socket accepting LMTP connections (such as is
580 supported by the Cyrus IMAP daemon) Example:
581 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
583 This option can be used with ODMR, and will make fetchmail a
585 relay between the ODMR server and SMTP or LMTP receiver.
586 --fetchdomains <hosts>
588 (Keyword: fetchdomains)
589 In ETRN or ODMR mode, this option specifies the list of domains
590 the server should ship mail for once the connection is turned
591 around. The default is the FQDN of the machine running fetch‐
592 mail.
593 -D <domain> | --smtpaddress <domain>
595 (Keyword: smtpaddress)
596 Specify the domain to be appended to addresses in RCPT TO lines
597 shipped to SMTP. When this is not specified, the name of the
598 SMTP server (as specified by --smtphost) is used for SMTP/LMTP
599 and 'localhost' is used for UNIX socket/BSMTP.
600 --smtpname <user@domain>
602 (Keyword: smtpname)
603 Specify the domain and user to be put in RCPT TO lines shipped
604 to SMTP. The default user is the current local user.
605 -Z <nnn> | --antispam <nnn[, nnn]...>
607 (Keyword: antispam)
608 Specifies the list of numeric SMTP errors that are to be inter‐
609 preted as a spam-block response from the listener. A value of
610 -1 disables this option. For the command-line option, the list
611 values should be comma-separated.
612 -m <command> | --mda <command>
614 (Keyword: mda)
615 This option lets fetchmail use a Message or Local Delivery Agent
616 (MDA or LDA) directly, rather than forward via SMTP or LMTP.
617 To avoid losing mail, use this option only with MDAs like mail‐
619 drop or MTAs like sendmail that exit with a nonzero status on
620 disk-full and other delivery errors; the nonzero status tells
621 fetchmail that delivery failed and prevents the message from
622 being deleted on the server.
623 If fetchmail is running as root, it sets its user id while
625 delivering mail through an MDA as follows: First, the FETCH‐
626 MAILUSER, LOGNAME, and USER environment variables are checked in
627 this order. The value of the first variable from his list that
628 is defined (even if it is empty!) is looked up in the system
629 user database. If none of the variables is defined, fetchmail
630 will use the real user id it was started with. If one of the
631 variables was defined, but the user stated there isn't found,
632 fetchmail continues running as root, without checking remaining
633 variables on the list. Practically, this means that if you run
634 fetchmail as root (not recommended), it is most useful to define
635 the FETCHMAILUSER environment variable to set the user that the
636 MDA should run as. Some MDAs (such as maildrop) are designed to
637 be setuid root and setuid to the recipient's user id, so you
638 don't lose functionality this way even when running fetchmail as
639 unprivileged user. Check the MDA's manual for details.
640 Some possible MDAs are "/usr/sbin/sendmail -i -f %F -- %T"
642 (Note: some several older or vendor sendmail versions mistake --
643 for an address, rather than an indicator to mark the end of the
644 option arguments), "/usr/bin/deliver" and "/usr/bin/maildrop -d
645 %T". Local delivery addresses will be inserted into the MDA
646 command wherever you place a %T; the mail message's From address
647 will be inserted where you place an %F.
648 Do NOT enclose the %F or %T string in single quotes! For both
650 %T and %F, fetchmail encloses the addresses in single quotes
651 ('), after removing any single quotes they may contain, before
652 the MDA command is passed to the shell.
653 Do NOT use an MDA invocation that dispatches on the contents of
655 To/Cc/Bcc, like "sendmail -i -t" or "qmail-inject", it will cre‐
656 ate mail loops and bring the just wrath of many postmasters down
657 upon your head. This is one of the most frequent configuration
658 errors!
659 Also, do not try to combine multidrop mode with an MDA such as
661 maildrop that can only accept one address, unless your upstream
662 stores one copy of the message per recipient and transports the
663 envelope recipient in a header; you will lose mail.
664 The well-known procmail(1) package is very hard to configure
666 properly, it has a very nasty "fall through to the next rule"
667 behavior on delivery errors (even temporary ones, such as out of
668 disk space if another user's mail daemon copies the mailbox
669 around to purge old messages), so your mail will end up in the
670 wrong mailbox sooner or later. The proper procmail configuration
671 is outside the scope of this document. Using maildrop(1) is usu‐
672 ally much easier, and many users find the filter syntax used by
673 maildrop easier to understand.
674 Finally, we strongly advise that you do not use qmail-inject.
676 The command line interface is non-standard without providing
677 benefits for typical use, and fetchmail makes no attempts to
678 accomodate qmail-inject's deviations from the standard. Some of
679 qmail-inject's command-line and environment options are actually
680 dangerous and can cause broken threads, non-detected duplicate
681 messages and forwarding loops.
682 --lmtp (Keyword: lmtp)
685 Cause delivery via LMTP (Local Mail Transfer Protocol). A ser‐
686 vice host and port must be explicitly specified on each host in
687 the smtphost hunt list (see above) if this option is selected;
688 the default port 25 will (in accordance with RFC 2033) not be
689 accepted.
690 --bsmtp <filename>
692 (Keyword: bsmtp)
693 Append fetched mail to a BSMTP file. This simply contains the
694 SMTP commands that would normally be generated by fetchmail when
695 passing mail to an SMTP listener daemon.
696 An argument of '-' causes the SMTP batch to be written to stan‐
698 dard output, which is of limited use: this only makes sense for
699 debugging, because fetchmail's regular output is interspersed on
700 the same channel, so this isn't suitable for mail delivery. This
701 special mode may be removed in a later release.
702 Note that fetchmail's reconstruction of MAIL FROM and RCPT TO
704 lines is not guaranteed correct; the caveats discussed under THE
705 USE AND ABUSE OF MULTIDROP MAILBOXES below apply. This mode has
706 precedence before --mda and SMTP/LMTP.
707 --bad-header {reject|accept}
709 (Keyword: bad-header; since v6.3.15)
710 Specify how fetchmail is supposed to treat messages with bad
711 headers, i. e. headers with bad syntax. Traditionally, fetchmail
712 has rejected such messages, but some distributors modified
713 fetchmail to accept them. You can now configure fetchmail's be‐
714 haviour per server.
715 Resource Limit Control Options
718 -l <maxbytes> | --limit <maxbytes>
719 (Keyword: limit)
720 Takes a maximum octet size argument, where 0 is the default and
721 also the special value designating "no limit". If nonzero, mes‐
722 sages larger than this size will not be fetched and will be left
723 on the server (in foreground sessions, the progress messages
724 will note that they are "oversized"). If the fetch protocol
725 permits (in particular, under IMAP or POP3 without the fetchall
726 option) the message will not be marked seen.
727 An explicit --limit of 0 overrides any limits set in your run
729 control file. This option is intended for those needing to
730 strictly control fetch time due to expensive and variable phone
731 rates.
732 Combined with --limitflush, it can be used to delete oversized
734 messages waiting on a server. In daemon mode, oversize notifi‐
735 cations are mailed to the calling user (see the --warnings
736 option). This option does not work with ETRN or ODMR.
737 -w <interval> | --warnings <interval>
739 (Keyword: warnings)
740 Takes an interval in seconds. When you call fetchmail with a
741 'limit' option in daemon mode, this controls the interval at
742 which warnings about oversized messages are mailed to the call‐
743 ing user (or the user specified by the 'postmaster' option).
744 One such notification is always mailed at the end of the the
745 first poll that the oversized message is detected. Thereafter,
746 re-notification is suppressed until after the warning interval
747 elapses (it will take place at the end of the first following
748 poll).
749 -b <count> | --batchlimit <count>
751 (Keyword: batchlimit)
752 Specify the maximum number of messages that will be shipped to
753 an SMTP listener before the connection is deliberately torn down
754 and rebuilt (defaults to 0, meaning no limit). An explicit
755 --batchlimit of 0 overrides any limits set in your run control
756 file. While sendmail(8) normally initiates delivery of a mes‐
757 sage immediately after receiving the message terminator, some
758 SMTP listeners are not so prompt. MTAs like smail(8) may wait
759 till the delivery socket is shut down to deliver. This may pro‐
760 duce annoying delays when fetchmail is processing very large
761 batches. Setting the batch limit to some nonzero size will pre‐
762 vent these delays. This option does not work with ETRN or ODMR.
763 -B <number> | --fetchlimit <number>
765 (Keyword: fetchlimit)
766 Limit the number of messages accepted from a given server in a
767 single poll. By default there is no limit. An explicit --fetch‐
768 limit of 0 overrides any limits set in your run control file.
769 This option does not work with ETRN or ODMR.
770 --fetchsizelimit <number>
772 (Keyword: fetchsizelimit)
773 Limit the number of sizes of messages accepted from a given
774 server in a single transaction. This option is useful in reduc‐
775 ing the delay in downloading the first mail when there are too
776 many mails in the mailbox. By default, the limit is 100. If
777 set to 0, sizes of all messages are downloaded at the start.
778 This option does not work with ETRN or ODMR. For POP3, the only
779 valid non-zero value is 1.
780 --fastuidl <number>
782 (Keyword: fastuidl)
783 Do a binary instead of linear search for the first unseen UID.
784 Binary search avoids downloading the UIDs of all mails. This
785 saves time (especially in daemon mode) where downloading the
786 same set of UIDs in each poll is a waste of bandwidth. The num‐
787 ber 'n' indicates how rarely a linear search should be done. In
788 daemon mode, linear search is used once followed by binary
789 searches in 'n-1' polls if 'n' is greater than 1; binary search
790 is always used if 'n' is 1; linear search is always used if 'n'
791 is 0. In non-daemon mode, binary search is used if 'n' is 1;
792 otherwise linear search is used. The default value of 'n' is 4.
793 This option works with POP3 only.
794 -e <count> | --expunge <count>
796 (Keyword: expunge)
797 Arrange for deletions to be made final after a given number of
798 messages. Under POP2 or POP3, fetchmail cannot make deletions
799 final without sending QUIT and ending the session -- with this
800 option on, fetchmail will break a long mail retrieval session
801 into multiple sub-sessions, sending QUIT after each sub-session.
802 This is a good defense against line drops on POP3 servers.
803 Under IMAP, fetchmail normally issues an EXPUNGE command after
804 each deletion in order to force the deletion to be done immedi‐
805 ately. This is safest when your connection to the server is
806 flaky and expensive, as it avoids resending duplicate mail after
807 a line hit. However, on large mailboxes the overhead of re-
808 indexing after every message can slam the server pretty hard, so
809 if your connection is reliable it is good to do expunges less
810 frequently. Also note that some servers enforce a delay of a
811 few seconds after each quit, so fetchmail may not be able to get
812 back in immediately after an expunge -- you may see "lock busy"
813 errors if this happens. If you specify this option to an integer
814 N, it tells fetchmail to only issue expunges on every Nth
815 delete. An argument of zero suppresses expunges entirely (so no
816 expunges at all will be done until the end of run). This option
817 does not work with ETRN or ODMR.
818 Authentication Options
821 -u <name> | --user <name> | --username <name>
822 (Keyword: user[name])
823 Specifies the user identification to be used when logging in to
824 the mailserver. The appropriate user identification is both
825 server and user-dependent. The default is your login name on
826 the client machine that is running fetchmail. See USER AUTHEN‐
827 TICATION below for a complete description.
828 -I <specification> | --interface <specification>
830 (Keyword: interface)
831 Require that a specific interface device be up and have a spe‐
832 cific local or remote IPv4 (IPv6 is not supported by this option
833 yet) address (or range) before polling. Frequently fetchmail is
834 used over a transient point-to-point TCP/IP link established
835 directly to a mailserver via SLIP or PPP. That is a relatively
836 secure channel. But when other TCP/IP routes to the mailserver
837 exist (e.g. when the link is connected to an alternate ISP),
838 your username and password may be vulnerable to snooping (espe‐
839 cially when daemon mode automatically polls for mail, shipping a
840 clear password over the net at predictable intervals). The
841 --interface option may be used to prevent this. When the speci‐
842 fied link is not up or is not connected to a matching IP
843 address, polling will be skipped. The format is:
844 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
846 The field before the first slash is the interface name (i.e.
848 sl0, ppp0 etc.). The field before the second slash is the
849 acceptable IP address. The field after the second slash is a
850 mask which specifies a range of IP addresses to accept. If no
851 mask is present 255.255.255.255 is assumed (i.e. an exact
852 match). This option is currently only supported under Linux and
853 FreeBSD. Please see the monitor section for below for FreeBSD
854 specific information.
855 Note that this option may be removed from a future fetchmail
857 version.
858 -M <interface> | --monitor <interface>
860 (Keyword: monitor)
861 Daemon mode can cause transient links which are automatically
862 taken down after a period of inactivity (e.g. PPP links) to
863 remain up indefinitely. This option identifies a system TCP/IP
864 interface to be monitored for activity. After each poll inter‐
865 val, if the link is up but no other activity has occurred on the
866 link, then the poll will be skipped. However, when fetchmail is
867 woken up by a signal, the monitor check is skipped and the poll
868 goes through unconditionally. This option is currently only
869 supported under Linux and FreeBSD. For the monitor and inter‐
870 face options to work for non root users under FreeBSD, the
871 fetchmail binary must be installed SGID kmem. This would be a
872 security hole, but fetchmail runs with the effective GID set to
873 that of the kmem group only when interface data is being col‐
874 lected.
875 Note that this option may be removed from a future fetchmail
877 version.
878 --auth <type>
880 (Keyword: auth[enticate])
881 This option permits you to specify an authentication type (see
882 USER AUTHENTICATION below for details). The possible values are
883 any, password, kerberos_v5, kerberos (or, for excruciating
884 exactness, kerberos_v4), gssapi, cram-md5, otp, ntlm, msn (only
885 for POP3), external (only IMAP) and ssh. When any (the default)
886 is specified, fetchmail tries first methods that don't require a
887 password (EXTERNAL, GSSAPI, KERBEROS IV, KERBEROS 5); then it
888 looks for methods that mask your password (CRAM-MD5, X-OTP -
889 note that NTLM and MSN are not autoprobed for POP3 and MSN is
890 only supported for POP3); and only if the server doesn't support
891 any of those will it ship your password en clair. Other values
892 may be used to force various authentication methods (ssh sup‐
893 presses authentication and is thus useful for IMAP PREAUTH).
894 (external suppresses authentication and is thus useful for IMAP
895 EXTERNAL). Any value other than password, cram-md5, ntlm, msn
896 or otp suppresses fetchmail's normal inquiry for a password.
897 Specify ssh when you are using an end-to-end secure connection
898 such as an ssh tunnel; specify external when you use TLS with
899 client authentication and specify gssapi or kerberos_v4 if you
900 are using a protocol variant that employs GSSAPI or K4. Choos‐
901 ing KPOP protocol automatically selects Kerberos authentication.
902 This option does not work with ETRN.
903 Miscellaneous Options
905 -f <pathname> | --fetchmailrc <pathname>
906 Specify a non-default name for the ~/.fetchmailrc run control
907 file. The pathname argument must be either "-" (a single dash,
908 meaning to read the configuration from standard input) or a
909 filename. Unless the --version option is also on, a named file
910 argument must have permissions no more open than 0700
911 (u=rwx,g=,o=) or else be /dev/null.
912 -i <pathname> | --idfile <pathname>
914 (Keyword: idfile)
915 Specify an alternate name for the .fetchids file used to save
916 message UIDs. NOTE: since fetchmail 6.3.0, write access to the
917 directory containing the idfile is required, as fetchmail writes
918 a temporary file and renames it into the place of the real
919 idfile only if the temporary file has been written successfully.
920 This avoids the truncation of idfiles when running out of disk
921 space.
922 --pidfile <pathname>
924 (Keyword: pidfile; since fetchmail v6.3.4)
925 Override the default location of the PID file. Default: see
926 "ENVIRONMENT" below.
927 -n | --norewrite
929 (Keyword: no rewrite)
930 Normally, fetchmail edits RFC-822 address headers (To, From, Cc,
931 Bcc, and Reply-To) in fetched mail so that any mail IDs local to
932 the server are expanded to full addresses (@ and the mailserver
933 hostname are appended). This enables replies on the client to
934 get addressed correctly (otherwise your mailer might think they
935 should be addressed to local users on the client machine!).
936 This option disables the rewrite. (This option is provided to
937 pacify people who are paranoid about having an MTA edit mail
938 headers and want to know they can prevent it, but it is gener‐
939 ally not a good idea to actually turn off rewrite.) When using
940 ETRN or ODMR, the rewrite option is ineffective.
941 -E <line> | --envelope <line>
943 (Keyword: envelope; Multidrop only)
944 In the configuration file, an enhanced syntax is used:
945 envelope [<count>] <line>
946 This option changes the header fetchmail assumes will carry a
948 copy of the mail's envelope address. Normally this is 'X-Enve‐
949 lope-To'. Other typically found headers to carry envelope
950 information are 'X-Original-To' and 'Delivered-To'. Now, since
951 these headers are not standardized, practice varies. See the
952 discussion of multidrop address handling below. As a special
953 case, 'envelope "Received"' enables parsing of sendmail-style
954 Received lines. This is the default, but discouraged because it
955 is not fully reliable.
956 Note that fetchmail expects the Received-line to be in a spe‐
958 cific format: It must contain "by host for address", where host
959 must match one of the mailserver names that fetchmail recognizes
960 for the account in question.
961 The optional count argument (only available in the configuration
963 file) determines how many header lines of this kind are skipped.
964 A count of 1 means: skip the first, take the second. A count of
965 2 means: skip the first and second, take the third, and so on.
966 -Q <prefix> | --qvirtual <prefix>
968 (Keyword: qvirtual; Multidrop only)
969 The string prefix assigned to this option will be removed from
970 the user name found in the header specified with the envelope
971 option (before doing multidrop name mapping or localdomain
972 checking, if either is applicable). This option is useful if you
973 are using fetchmail to collect the mail for an entire domain and
974 your ISP (or your mail redirection provider) is using qmail.
975 One of the basic features of qmail is the Delivered-To: message
976 header. Whenever qmail delivers a message to a local mailbox it
977 puts the username and hostname of the envelope recipient on this
978 line. The major reason for this is to prevent mail loops. To
979 set up qmail to batch mail for a disconnected site the ISP-mail‐
980 host will have normally put that site in its 'Virtualhosts' con‐
981 trol file so it will add a prefix to all mail addresses for this
982 site. This results in mail sent to 'username@userhost.user‐
983 dom.dom.com' having a Delivered-To: line of the form:
984 Delivered-To: mbox-userstr-username@userhost.example.com
986 The ISP can make the 'mbox-userstr-' prefix anything they choose but a
988 string matching the user host name is likely. By using the option
989 'envelope Delivered-To:' you can make fetchmail reliably identify the
990 original envelope recipient, but you have to strip the 'mbox-userstr-'
991 prefix to deliver to the correct user. This is what this option is
992 for.
993 --configdump
995 Parse the ~/.fetchmailrc file, interpret any command-line
996 options specified, and dump a configuration report to standard
997 output. The configuration report is a data structure assignment
998 in the language Python. This option is meant to be used with an
999 interactive ~/.fetchmailrc editor like fetchmailconf, written in
1000 Python.
1001 Removed Options
1004 -T | --netsec
1005 Removed before version 6.3.0, the required underlying inet6_apps
1006 library had been discontinued and is no longer available.
1007
1010 All modes except ETRN require authentication of the client to the
1011 server. Normal user authentication in fetchmail is very much like the
1012 authentication mechanism of ftp(1). The correct user-id and password
1013 depend upon the underlying security system at the mailserver.
1014 If the mailserver is a Unix machine on which you have an ordinary user
1016 account, your regular login name and password are used with fetchmail.
1017 If you use the same login name on both the server and the client
1018 machines, you needn't worry about specifying a user-id with the -u
1019 option -- the default behavior is to use your login name on the client
1020 machine as the user-id on the server machine. If you use a different
1021 login name on the server machine, specify that login name with the -u
1022 option. e.g. if your login name is 'jsmith' on a machine named 'mail‐
1023 grunt', you would start fetchmail as follows:
1024 fetchmail -u jsmith mailgrunt
1026 The default behavior of fetchmail is to prompt you for your mailserver
1028 password before the connection is established. This is the safest way
1029 to use fetchmail and ensures that your password will not be compro‐
1030 mised. You may also specify your password in your ~/.fetchmailrc file.
1031 This is convenient when using fetchmail in daemon mode or with scripts.
1032 Using netrc files
1035 If you do not specify a password, and fetchmail cannot extract one from
1036 your ~/.fetchmailrc file, it will look for a ~/.netrc file in your home
1037 directory before requesting one interactively; if an entry matching the
1038 mailserver is found in that file, the password will be used. Fetchmail
1039 first looks for a match on poll name; if it finds none, it checks for a
1040 match on via name. See the ftp(1) man page for details of the syntax
1041 of the ~/.netrc file. To show a practical example, a .netrc might look
1042 like this:
1043 machine hermes.example.org
1045 login joe
1046 password topsecret
1047 You can repeat this block with different user information if you need
1049 to provide more than one password.
1050 This feature may allow you to avoid duplicating password information in
1052 more than one file.
1053 On mailservers that do not provide ordinary user accounts, your user-id
1055 and password are usually assigned by the server administrator when you
1056 apply for a mailbox on the server. Contact your server administrator
1057 if you don't know the correct user-id and password for your mailbox
1058 account.
1059
1061 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
1062 independent authentication using the .rhosts file on the mailserver
1063 side. Under this RPOP variant, a fixed per-user ID equivalent to a
1064 password was sent in clear over a link to a reserved port, with the
1065 command RPOP rather than PASS to alert the server that it should do
1066 special checking. RPOP is supported by fetchmail (you can specify
1067 'protocol RPOP' to have the program send 'RPOP' rather than 'PASS') but
1068 its use is strongly discouraged, and support will be removed from a
1069 future fetchmail version. This facility was vulnerable to spoofing and
1070 was withdrawn in RFC1460.
1071 RFC1460 introduced APOP authentication. In this variant of POP3, you
1073 register an APOP password on your server host (on some servers, the
1074 program to do this is called popauth(8)). You put the same password in
1075 your ~/.fetchmailrc file. Each time fetchmail logs in, it sends an MD5
1076 hash of your password and the server greeting time to the server, which
1077 can verify it by checking its authorization database.
1078 Note that APOP is no longer considered resistant against man-in-the-
1080 middle attacks.
1081 RETR or TOP
1083 fetchmail makes some efforts to make the server believe messages had
1084 not been retrieved, by using the TOP command with a large number of
1085 lines when possible. TOP is a command that retrieves the full header
1086 and a fetchmail-specified amount of body lines. It is optional and
1087 therefore not implemented by all servers, and some are known to imple‐
1088 ment it improperly. On many servers however, the RETR command which
1089 retrieves the full message with header and body, sets the "seen" flag
1090 (for instance, in a web interface), whereas the TOP command does not do
1091 that.
1092 fetchmail will always use the RETR command if "fetchall" is set.
1094 fetchmail will also use the RETR command if "keep" is set and "uidl" is
1095 unset. Finally, fetchmail will use the RETR command on Maillennium
1096 POP3/PROXY servers (used by Comcast) to avoid a deliberate TOP misin‐
1097 terpretation in this server that causes message corruption.
1098 In all other cases, fetchmail will use the TOP command. This implies
1100 that in "keep" setups, "uidl" must be set if "TOP" is desired.
1101 Note that this description is true for the current version of fetch‐
1103 mail, but the behavior may change in future versions. In particular,
1104 fetchmail may prefer the RETR command because the TOP command causes
1105 much grief on some servers and is only optional.
1106
1108 If your fetchmail was built with Kerberos support and you specify Ker‐
1109 beros authentication (either with --auth or the .fetchmailrc option
1110 authenticate kerberos_v4) it will try to get a Kerberos ticket from the
1111 mailserver at the start of each query. Note: if either the pollname or
1112 via name is 'hesiod', fetchmail will try to use Hesiod to look up the
1113 mailserver.
1114 If you use POP3 or IMAP with GSSAPI authentication, fetchmail will
1116 expect the server to have RFC1731- or RFC1734-conforming GSSAPI capa‐
1117 bility, and will use it. Currently this has only been tested over Ker‐
1118 beros V, so you're expected to already have a ticket-granting ticket.
1119 You may pass a username different from your principal name using the
1120 standard --user command or by the .fetchmailrc option user.
1121 If your IMAP daemon returns the PREAUTH response in its greeting line,
1123 fetchmail will notice this and skip the normal authentication step.
1124 This can be useful, e.g. if you start imapd explicitly using ssh. In
1125 this case you can declare the authentication value 'ssh' on that site
1126 entry to stop .fetchmail from asking you for a password when it starts
1127 up.
1128 If you use client authentication with TLS1 and your IMAP daemon returns
1130 the AUTH=EXTERNAL response, fetchmail will notice this and will use the
1131 authentication shortcut and will not send the passphrase. In this case
1132 you can declare the authentication value 'external'
1133 on that site to stop fetchmail from asking you for a password when it
1134 starts up.
1135 If you are using POP3, and the server issues a one-time-password chal‐
1137 lenge conforming to RFC1938, fetchmail will use your password as a pass
1138 phrase to generate the required response. This avoids sending secrets
1139 over the net unencrypted.
1140 Compuserve's RPA authentication is supported. If you compile in the
1142 support, fetchmail will try to perform an RPA pass-phrase authentica‐
1143 tion instead of sending over the password en clair if it detects "@com‐
1144 puserve.com" in the hostname.
1145 If you are using IMAP, Microsoft's NTLM authentication (used by Micro‐
1147 soft Exchange) is supported. If you compile in the support, fetchmail
1148 will try to perform an NTLM authentication (instead of sending over the
1149 password en clair) whenever the server returns AUTH=NTLM in its capa‐
1150 bility response. Specify a user option value that looks like
1151 'user@domain': the part to the left of the @ will be passed as the
1152 username and the part to the right as the NTLM domain.
1153 Secure Socket Layers (SSL) and Transport Layer Security (TLS)
1156 Note that fetchmail currently uses the OpenSSL library, which is se‐
1157 verely underdocumented, so failures may occur just because the program‐
1158 mers are not aware of OpenSSL's requirement of the day. For instance,
1159 since v6.3.16, fetchmail calls OpenSSL_add_all_algorithms(), which is
1160 necessary to support certificates with SHA256 on OpenSSL 0.9.8 -- this
1161 information is deeply hidden in the documentation and not at all obvi‐
1162 ous. Please do not hesitate to report subtle SSL failures.
1163 You can access SSL encrypted services by specifying the --ssl option.
1165 You can also do this using the "ssl" user option in the .fetchmailrc
1166 file. With SSL encryption enabled, queries are initiated over a connec‐
1167 tion after negotiating an SSL session, and the connection fails if SSL
1168 cannot be negotiated. Some services, such as POP3 and IMAP, have dif‐
1169 ferent well known ports defined for the SSL encrypted services. The
1170 encrypted ports will be selected automatically when SSL is enabled and
1171 no explicit port is specified. The --sslproto 'SSL3' option should be
1172 used to select the SSLv3 protocol (default if unset: v2 or v3). Also,
1173 the --sslcertck command line or sslcertck run control file option
1174 should be used to force strict certificate checking - see below.
1175 If SSL is not configured, fetchmail will usually opportunistically try
1177 to use STARTTLS. STARTTLS can be enforced by using --sslproto "TLS1".
1178 TLS connections use the same port as the unencrypted version of the
1179 protocol and negotiate TLS via special command. The --sslcertck command
1180 line or sslcertck run control file option should be used to force
1181 strict certificate checking - see below.
1182 --sslcertck is recommended: When connecting to an SSL or TLS encrypted
1184 server, the server presents a certificate to the client for validation.
1185 The certificate is checked to verify that the common name in the cer‐
1186 tificate matches the name of the server being contacted and that the
1187 effective and expiration dates in the certificate indicate that it is
1188 currently valid. If any of these checks fail, a warning message is
1189 printed, but the connection continues. The server certificate does not
1190 need to be signed by any specific Certifying Authority and may be a
1191 "self-signed" certificate. If the --sslcertck command line option or
1192 sslcertck run control file option is used, fetchmail will instead abort
1193 if any of these checks fail, because it must assume that there is a
1194 man-in-the-middle attack in this scenario, hence fetchmail must not
1195 expose cleartest passwords. Use of the sslcertck or --sslcertck option
1196 is therefore advised.
1197 Some SSL encrypted servers may request a client side certificate. A
1199 client side public SSL certificate and private SSL key may be speci‐
1200 fied. If requested by the server, the client certificate is sent to
1201 the server for validation. Some servers may require a valid client
1202 certificate and may refuse connections if a certificate is not provided
1203 or if the certificate is not valid. Some servers may require client
1204 side certificates be signed by a recognized Certifying Authority. The
1205 format for the key files and the certificate files is that required by
1206 the underlying SSL libraries (OpenSSL in the general case).
1207 A word of care about the use of SSL: While above mentioned setup with
1209 self-signed server certificates retrieved over the wires can protect
1210 you from a passive eavesdropper, it doesn't help against an active
1211 attacker. It's clearly an improvement over sending the passwords in
1212 clear, but you should be aware that a man-in-the-middle attack is triv‐
1213 ially possible (in particular with tools such as dsniff ⟨http://
1214 monkey.org/~dugsong/dsniff/⟩, ). Use of strict certificate checking
1215 with a certification authority recognized by server and client, or per‐
1216 haps of an SSH tunnel (see below for some examples) is preferable if
1217 you care seriously about the security of your mailbox and passwords.
1218 ESMTP AUTH
1221 fetchmail also supports authentication to the ESMTP server on the
1222 client side according to RFC 2554. You can specify a name/password
1223 pair to be used with the keywords 'esmtpname' and 'esmtppassword'; the
1224 former defaults to the username of the calling user.
1225
1228 Introducing the daemon mode
1229 In daemon mode, fetchmail puts itself into the background and runs for‐
1230 ever, querying each specified host and then sleeping for a given
1231 polling interval.
1232 Starting the daemon mode
1234 There are several ways to make fetchmail work in daemon mode. On the
1235 command line, --daemon <interval> or -d <interval> option runs fetch‐
1236 mail in daemon mode. You must specify a numeric argument which is a
1237 polling interval (time to wait after completing a whole poll cycle with
1238 the last server and before starting the next poll cycle with the first
1239 server) in seconds.
1240 Example: simply invoking
1242 fetchmail -d 900
1244 will, therefore, poll all the hosts described in your ~/.fetchmailrc
1246 file (except those explicitly excluded with the 'skip' verb) a bit less
1247 often than once every 15 minutes (exactly: 15 minutes + time that the
1248 poll takes).
1249 It is also possible to set a polling interval in your ~/.fetchmailrc
1251 file by saying 'set daemon <interval>', where <interval> is an integer
1252 number of seconds. If you do this, fetchmail will always start in dae‐
1253 mon mode unless you override it with the command-line option --daemon 0
1254 or -d0.
1255 Only one daemon process is permitted per user; in daemon mode, fetch‐
1257 mail sets up a per-user lockfile to guarantee this. (You can however
1258 cheat and set the FETCHMAILHOME environment variable to overcome this
1259 setting, but in that case, it is your responsibility to make sure you
1260 aren't polling the same server with two processes at the same time.)
1261 Awakening the background daemon
1263 Normally, calling fetchmail with a daemon in the background sends a
1264 wake-up signal to the daemon and quits without output. The background
1265 daemon then starts its next poll cycle immediately. The wake-up sig‐
1266 nal, SIGUSR1, can also be sent manually. The wake-up action also clears
1267 any 'wedged' flags indicating that connections have wedged due to
1268 failed authentication or multiple timeouts.
1269 Terminating the background daemon
1271 The option --quit will kill a running daemon process instead of waking
1272 it up (if there is no such process, fetchmail will notify you). If the
1273 --quit option appears last on the command line, fetchmail will kill the
1274 running daemon process and then quit. Otherwise, fetchmail will first
1275 kill a running daemon process and then continue running with the other
1276 options.
1277 Useful options for daemon mode
1279 The -L <filename> or --logfile <filename> option (keyword: set logfile)
1280 is only effective when fetchmail is detached and in daemon mode. Note
1281 that the logfile must exist before fetchmail is run, you can use the
1282 touch(1) command with the filename as its sole argument to create it.
1283 This option allows you to redirect status messages into a specified
1284 logfile (follow the option with the logfile name). The logfile is
1285 opened for append, so previous messages aren't deleted. This is pri‐
1286 marily useful for debugging configurations. Note that fetchmail does
1287 not detect if the logfile is rotated, the logfile is only opened once
1288 when fetchmail starts. You need to restart fetchmail after rotating the
1289 logfile and before compressing it (if applicable).
1290 The --syslog option (keyword: set syslog) allows you to redirect status
1292 and error messages emitted to the syslog(3) system daemon if available.
1293 Messages are logged with an id of fetchmail, the facility LOG_MAIL, and
1294 priorities LOG_ERR, LOG_ALERT or LOG_INFO. This option is intended for
1295 logging status and error messages which indicate the status of the dae‐
1296 mon and the results while fetching mail from the server(s). Error mes‐
1297 sages for command line options and parsing the .fetchmailrc file are
1298 still written to stderr, or to the specified log file. The --nosyslog
1299 option turns off use of syslog(3), assuming it's turned on in the
1300 ~/.fetchmailrc file.
1301 The -N or --nodetach option suppresses backgrounding and detachment of
1303 the daemon process from its control terminal. This is useful for
1304 debugging or when fetchmail runs as the child of a supervisor process
1305 such as init(8) or Gerrit Pape's runit(8). Note that this also causes
1306 the logfile option to be ignored (though perhaps it shouldn't).
1307 Note that while running in daemon mode polling a POP2 or IMAP2bis
1309 server, transient errors (such as DNS failures or sendmail delivery
1310 refusals) may force the fetchall option on for the duration of the next
1311 polling cycle. This is a robustness feature. It means that if a mes‐
1312 sage is fetched (and thus marked seen by the mailserver) but not deliv‐
1313 ered locally due to some transient error, it will be re-fetched during
1314 the next poll cycle. (The IMAP logic doesn't delete messages until
1315 they're delivered, so this problem does not arise.)
1316 If you touch or change the ~/.fetchmailrc file while fetchmail is run‐
1318 ning in daemon mode, this will be detected at the beginning of the next
1319 poll cycle. When a changed ~/.fetchmailrc is detected, fetchmail
1320 rereads it and restarts from scratch (using exec(2); no state informa‐
1321 tion is retained in the new instance). Note that if fetchmail needs to
1322 query for passwords, of that if you break the ~/.fetchmailrc file's
1323 syntax, the new instance will softly and silently vanish away on
1324 startup.
1325
1328 The --postmaster <name> option (keyword: set postmaster) specifies the
1329 last-resort username to which multidrop mail is to be forwarded if no
1330 matching local recipient can be found. It is also used as destination
1331 of undeliverable mail if the 'bouncemail' global option is off and
1332 additionally for spam-blocked mail if the 'bouncemail' global option is
1333 off and the 'spambounce' global option is on. This option defaults to
1334 the user who invoked fetchmail. If the invoking user is root, then the
1335 default of this option is the user 'postmaster'. Setting postmaster to
1336 the empty string causes such mail as described above to be discarded -
1337 this however is usually a bad idea. See also the description of the
1338 'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.
1339 The --nobounce behaves like the "set no bouncemail" global option,
1341 which see.
1342 The --invisible option (keyword: set invisible) tries to make fetchmail
1344 invisible. Normally, fetchmail behaves like any other MTA would -- it
1345 generates a Received header into each message describing its place in
1346 the chain of transmission, and tells the MTA it forwards to that the
1347 mail came from the machine fetchmail itself is running on. If the
1348 invisible option is on, the Received header is suppressed and fetchmail
1349 tries to spoof the MTA it forwards to into thinking it came directly
1350 from the mailserver host.
1351 The --showdots option (keyword: set showdots) forces fetchmail to show
1353 progress dots even if the output goes to a file or fetchmail is not in
1354 verbose mode. Fetchmail shows the dots by default when run in --ver‐
1355 bose mode and output goes to console. This option is ignored in
1356 --silent mode.
1357 By specifying the --tracepolls option, you can ask fetchmail to add
1359 information to the Received header on the form "polling {label} account
1360 {user}", where {label} is the account label (from the specified rcfile,
1361 normally ~/.fetchmailrc) and {user} is the username which is used to
1362 log on to the mail server. This header can be used to make filtering
1363 email where no useful header information is available and you want mail
1364 from different accounts sorted into different mailboxes (this could,
1365 for example, occur if you have an account on the same server running a
1366 mailing list, and are subscribed to the list using that account). The
1367 default is not adding any such header. In .fetchmailrc, this is called
1368 'tracepolls'.
1369
1372 The protocols fetchmail uses to talk to mailservers are next to bullet‐
1373 proof. In normal operation forwarding to port 25, no message is ever
1374 deleted (or even marked for deletion) on the host until the SMTP lis‐
1375 tener on the client side has acknowledged to fetchmail that the message
1376 has been either accepted for delivery or rejected due to a spam block.
1377 When forwarding to an MDA, however, there is more possibility of error.
1379 Some MDAs are 'safe' and reliably return a nonzero status on any deliv‐
1380 ery error, even one due to temporary resource limits. The maildrop(1)
1381 program is like this; so are most programs designed as mail transport
1382 agents, such as sendmail(1), including the sendmail wrapper of Postfix
1383 and exim(1). These programs give back a reliable positive acknowledge‐
1384 ment and can be used with the mda option with no risk of mail loss.
1385 Unsafe MDAs, though, may return 0 even on delivery failure. If this
1386 happens, you will lose mail.
1387 The normal mode of fetchmail is to try to download only 'new' messages,
1389 leaving untouched (and undeleted) messages you have already read
1390 directly on the server (or fetched with a previous fetchmail --keep).
1391 But you may find that messages you've already read on the server are
1392 being fetched (and deleted) even when you don't specify --all. There
1393 are several reasons this can happen.
1394 One could be that you're using POP2. The POP2 protocol includes no
1396 representation of 'new' or 'old' state in messages, so fetchmail must
1397 treat all messages as new all the time. But POP2 is obsolete, so this
1398 is unlikely.
1399 A potential POP3 problem might be servers that insert messages in the
1401 middle of mailboxes (some VMS implementations of mail are rumored to do
1402 this). The fetchmail code assumes that new messages are appended to
1403 the end of the mailbox; when this is not true it may treat some old
1404 messages as new and vice versa. Using UIDL whilst setting fastuidl 0
1405 might fix this, otherwise, consider switching to IMAP.
1406 Yet another POP3 problem is that if they can't make tempfiles in the
1408 user's home directory, some POP3 servers will hand back an undocumented
1409 response that causes fetchmail to spuriously report "No mail".
1410 The IMAP code uses the presence or absence of the server flag \Seen to
1412 decide whether or not a message is new. This isn't the right thing to
1413 do, fetchmail should check the UIDVALIDITY and use UID, but it doesn't
1414 do that yet. Under Unix, it counts on your IMAP server to notice the
1415 BSD-style Status flags set by mail user agents and set the \Seen flag
1416 from them when appropriate. All Unix IMAP servers we know of do this,
1417 though it's not specified by the IMAP RFCs. If you ever trip over a
1418 server that doesn't, the symptom will be that messages you have already
1419 read on your host will look new to the server. In this (unlikely)
1420 case, only messages you fetched with fetchmail --keep will be both
1421 undeleted and marked old.
1422 In ETRN and ODMR modes, fetchmail does not actually retrieve messages;
1424 instead, it asks the server's SMTP listener to start a queue flush to
1425 the client via SMTP. Therefore it sends only undelivered messages.
1426
1429 Many SMTP listeners allow administrators to set up 'spam filters' that
1430 block unsolicited email from specified domains. A MAIL FROM or DATA
1431 line that triggers this feature will elicit an SMTP response which
1432 (unfortunately) varies according to the listener.
1433 Newer versions of sendmail return an error code of 571.
1435 According to RFC2821, the correct thing to return in this situation is
1437 550 "Requested action not taken: mailbox unavailable" (the draft adds
1438 "[E.g., mailbox not found, no access, or command rejected for policy
1439 reasons].").
1440 Older versions of the exim MTA return 501 "Syntax error in parameters
1442 or arguments".
1443 The postfix MTA runs 554 as an antispam response.
1445 Zmailer may reject code with a 500 response (followed by an enhanced
1447 status code that contains more information).
1448 Return codes which fetchmail treats as antispam responses and discards
1450 the message can be set with the 'antispam' option. This is one of the
1451 only three circumstance under which fetchmail ever discards mail (the
1452 others are the 552 and 553 errors described below, and the suppression
1453 of multidropped messages with a message-ID already seen).
1454 If fetchmail is fetching from an IMAP server, the antispam response
1456 will be detected and the message rejected immediately after the headers
1457 have been fetched, without reading the message body. Thus, you won't
1458 pay for downloading spam message bodies.
1459 By default, the list of antispam responses is empty.
1461 If the spambounce global option is on, mail that is spam-blocked trig‐
1463 gers an RFC1892/RFC1894 bounce message informing the originator that we
1464 do not accept mail from it. See also BUGS.
1465
1468 Besides the spam-blocking described above, fetchmail takes special
1469 actions on the following SMTP/ESMTP error responses
1470 452 (insufficient system storage)
1472 Leave the message in the server mailbox for later retrieval.
1473 552 (message exceeds fixed maximum message size)
1475 Delete the message from the server. Send bounce-mail to the orig‐
1476 inator.
1477 553 (invalid sending domain)
1479 Delete the message from the server. Don't even try to send
1480 bounce-mail to the originator.
1481 Other errors trigger bounce mail back to the originator. See also BUGS.
1483
1486 The preferred way to set up fetchmail is to write a .fetchmailrc file
1487 in your home directory (you may do this directly, with a text editor,
1488 or indirectly via fetchmailconf). When there is a conflict between the
1489 command-line arguments and the arguments in this file, the command-line
1490 arguments take precedence.
1491 To protect the security of your passwords, your ~/.fetchmailrc may not
1493 normally have more than 0700 (u=rwx,g=,o=) permissions; fetchmail will
1494 complain and exit otherwise (this check is suppressed when --version is
1495 on).
1496 You may read the .fetchmailrc file as a list of commands to be executed
1498 when fetchmail is called with no arguments.
1499 Run Control Syntax
1501 Comments begin with a '#' and extend through the end of the line. Oth‐
1502 erwise the file consists of a series of server entries or global option
1503 statements in a free-format, token-oriented syntax.
1504 There are four kinds of tokens: grammar keywords, numbers (i.e. decimal
1506 digit sequences), unquoted strings, and quoted strings. A quoted
1507 string is bounded by double quotes and may contain whitespace (and
1508 quoted digits are treated as a string). Note that quoted strings will
1509 also contain line feed characters if they run across two or more lines,
1510 unless you use a backslash to join lines (see below). An unquoted
1511 string is any whitespace-delimited token that is neither numeric,
1512 string quoted nor contains the special characters ',', ';', ':', or
1513 '='.
1514 Any amount of whitespace separates tokens in server entries, but is
1516 otherwise ignored. You may use backslash escape sequences (\n for LF,
1517 \t for HT, \b for BS, \r for CR, \nnn for decimal (where nnn cannot
1518 start with a 0), \0ooo for octal, and \xhh for hex) to embed non-print‐
1519 able characters or string delimiters in strings. In quoted strings, a
1520 backslash at the very end of a line will cause the backslash itself and
1521 the line feed (LF or NL, new line) character to be ignored, so that you
1522 can wrap long strings. Without the backslash at the line end, the line
1523 feed character would become part of the string.
1524 Warning: while these resemble C-style escape sequences, they are not
1526 the same. fetchmail only supports these eight styles. C supports more
1527 escape sequences that consist of backslash (\) and a single character,
1528 but does not support decimal codes and does not require the leading 0
1529 in octal notation. Example: fetchmail interprets \233 the same as \xE9
1530 (Latin small letter e with acute), where C would interpret \233 as
1531 octal 0233 = \x9B (CSI, control sequence introducer).
1532 Each server entry consists of one of the keywords 'poll' or 'skip',
1534 followed by a server name, followed by server options, followed by any
1535 number of user (or username) descriptions, followed by user options.
1536 Note: the most common cause of syntax errors is mixing up user and
1537 server options or putting user options before the user descriptions.
1538 For backward compatibility, the word 'server' is a synonym for 'poll'.
1540 You can use the noise keywords 'and', 'with', 'has', 'wants', and
1542 'options' anywhere in an entry to make it resemble English. They're
1543 ignored, but but can make entries much easier to read at a glance. The
1544 punctuation characters ':', ';' and ',' are also ignored.
1545 Poll vs. Skip
1547 The 'poll' verb tells fetchmail to query this host when it is run with
1548 no arguments. The 'skip' verb tells fetchmail not to poll this host
1549 unless it is explicitly named on the command line. (The 'skip' verb
1550 allows you to experiment with test entries safely, or easily disable
1551 entries for hosts that are temporarily down.)
1552 Keyword/Option Summary
1554 Here are the legal options. Keyword suffixes enclosed in square brack‐
1555 ets are optional. Those corresponding to short command-line options
1556 are followed by '-' and the appropriate option letter. If option is
1557 only relevant to a single mode of operation, it is noted as 's' or 'm'
1558 for singledrop- or multidrop-mode, respectively.
1559 Here are the legal global options:
1561 Keyword Opt Mode Function
1564 ────────────────────────────────────────────────────────────────────
1565 set daemon -d Set a background poll interval in
1566 seconds.
1567 set postmaster Give the name of the last-resort
1568 mail recipient (default: user run‐
1569 ning fetchmail, "postmaster" if
1570 run by the root user)
1571 set bouncemail Direct error mail to the sender
1572 (default)
1573 set no bouncemail Direct error mail to the local
1574 postmaster (as per the 'postmas‐
1575 ter' global option above).
1576 set no spambounce Do not bounce spam-blocked mail
1577 (default).
1578 set spambounce Bounce blocked spam-blocked mail
1579 (as per the 'antispam' user
1580 option) back to the destination as
1581 indicated by the 'bouncemail'
1582 global option. Warning: Do not
1583 use this to bounce spam back to
1584 the sender - most spam is sent
1585 with false sender address and thus
1586 this option hurts innocent
1587 bystanders.
1588 set no softbounce Delete permanently undeliverable
1589 mail. It is recommended to use
1590 this option if the configuration
1591 has been thoroughly tested.
1592 set softbounce Keep permanently undeliverable
1593 mail as though a temporary error
1594 had occurred (default).
1595 set logfile -L Name of a file to append error and
1596 status messages to.
1597 set idfile -i Name of the file to store UID
1598 lists in.
1599 set syslog Do error logging through sys‐
1600 log(3).
1601 set no syslog Turn off error logging through
1602 syslog(3). (default)
1603 set properties String value that is ignored by
1604 fetchmail (may be used by exten‐
1605 sion scripts).
1606 Here are the legal server options:
1608 Keyword Opt Mode Function
1611 ─────────────────────────────────────────────────────────────────
1612 via Specify DNS name of mailserver,
1613 overriding poll name
1614 proto[col] -p Specify protocol (case insensi‐
1615 tive): POP2, POP3, IMAP, APOP,
1616 KPOP
1617 local[domains] m Specify domain(s) to be regarded
1618 as local
1619 port Specify TCP/IP service port (obso‐
1620 lete, use 'service' instead).
1621 service -P Specify service name (a numeric
1623 value is also allowed and consid‐
1624 ered a TCP/IP port number).
1625 auth[enticate] Set authentication type (default
1626 'any')
1627 timeout -t Server inactivity timeout in sec‐
1628 onds (default 300)
1629 envelope -E m Specify envelope-address header
1630 name
1631 no envelope m Disable looking for envelope
1632 address
1633 qvirtual -Q m Qmail virtual domain prefix to
1634 remove from user name
1635 aka m Specify alternate DNS names of
1636 mailserver
1637 interface -I specify IP interface(s) that must
1638 be up for server poll to take
1639 place
1640 monitor -M Specify IP address to monitor for
1641 activity
1642 plugin Specify command through which to
1643 make server connections.
1644 plugout Specify command through which to
1645 make listener connections.
1646 dns m Enable DNS lookup for multidrop
1647 (default)
1648 no dns m Disable DNS lookup for multidrop
1649 checkalias m Do comparison by IP address for
1650 multidrop
1651 no checkalias m Do comparison by name for mul‐
1652 tidrop (default)
1653 uidl -U Force POP3 to use client-side
1654 UIDLs (recommended)
1655 no uidl Turn off POP3 use of client-side
1656 UIDLs (default)
1657 interval Only check this site every N poll
1658 cycles; N is a numeric argument.
1659 tracepolls Add poll tracing information to
1660 the Received header
1661 principal Set Kerberos principal (only use‐
1662 ful with IMAP and kerberos)
1663 esmtpname Set name for RFC2554 authentica‐
1664 tion to the ESMTP server.
1665 esmtppassword Set password for RFC2554 authenti‐
1666 cation to the ESMTP server.
1667 bad-header How to treat messages with a bad
1668 header. Can be reject (default) or
1669 accept.
1670 Here are the legal user descriptions and options:
1672 Keyword Opt Mode Function
1675 ───────────────────────────────────────────────────────────────────
1676 user[name] -u This is the user description and
1677 must come first after server
1678 description and after possible
1679 server options, and before user
1680 options.
1681 It sets the remote user name if by
1682 itself or followed by 'there', or
1683 the local user name if followed by
1684 'here'.
1685 is Connect local and remote user
1686 names
1687 to Connect local and remote user
1688 names
1689 pass[word] Specify remote account password
1690 ssl Connect to server over the speci‐
1691 fied base protocol using SSL
1692 encryption
1693 sslcert Specify file for client side pub‐
1694 lic SSL certificate
1695 sslcertfile Specify file with trusted CA cer‐
1696 tificates
1697 sslcertpath Specify c_rehash-ed directory with
1699 trusted CA certificates.
1700 sslkey Specify file for client side pri‐
1701 vate SSL key
1702 sslproto Force ssl protocol for connection
1703 folder -r Specify remote folder to query
1704 smtphost -S Specify smtp host(s) to forward to
1705 fetchdomains m Specify domains for which mail
1706 should be fetched
1707 smtpaddress -D Specify the domain to be put in
1708 RCPT TO lines
1709 smtpname Specify the user and domain to be
1710 put in RCPT TO lines
1711 antispam -Z Specify what SMTP returns are
1712 interpreted as spam-policy blocks
1713 mda -m Specify MDA for local delivery
1714 bsmtp -o Specify BSMTP batch file to append
1715 to
1716 preconnect Command to be executed before each
1717 connection
1718 postconnect Command to be executed after each
1719 connection
1720 keep -k Don't delete seen messages from
1721 server (for POP3, uidl is recom‐
1722 mended)
1723 flush -F Flush all seen messages before
1724 querying (DANGEROUS)
1725 limitflush Flush all oversized messages
1726 before querying
1727 fetchall -a Fetch all messages whether seen or
1728 not
1729 rewrite Rewrite destination addresses for
1730 reply (default)
1731 stripcr Strip carriage returns from ends
1732 of lines
1733 forcecr Force carriage returns at ends of
1734 lines
1735 pass8bits Force BODY=8BITMIME to ESMTP lis‐
1736 tener
1737 dropstatus Strip Status and X-Mozilla-Status
1738 lines out of incoming mail
1739 dropdelivered Strip Delivered-To lines out of
1740 incoming mail
1741 mimedecode Convert quoted-printable to 8-bit
1742 in MIME messages
1743 idle Idle waiting for new messages
1744 after each poll (IMAP only)
1745 no keep -K Delete seen messages from server
1746 (default)
1747 no flush Don't flush all seen messages
1748 before querying (default)
1749 no fetchall Retrieve only new messages
1750 (default)
1751 no rewrite Don't rewrite headers
1752 no stripcr Don't strip carriage returns
1753 (default)
1754 no forcecr Don't force carriage returns at
1755 EOL (default)
1756 no pass8bits Don't force BODY=8BITMIME to ESMTP
1757 listener (default)
1758 no dropstatus Don't drop Status headers
1759 (default)
1760 no dropdelivered Don't drop Delivered-To headers
1761 (default)
1762 no mimedecode Don't convert quoted-printable to
1763 8-bit in MIME messages (default)
1764 no idle Don't idle waiting for new mes‐
1765 sages after each poll (IMAP only)
1766 limit -l Set message size limit
1767 warnings -w Set message size warning interval
1768 batchlimit -b Max # messages to forward in sin‐
1769 gle connect
1770 fetchlimit -B Max # messages to fetch in single
1771 connect
1772 fetchsizelimit Max # message sizes to fetch in
1775 single transaction
1776 fastuidl Use binary search for first unseen
1777 message (POP3 only)
1778 expunge -e Perform an expunge on every #th
1779 message (IMAP and POP3 only)
1780 properties String value is ignored by fetch‐
1781 mail (may be used by extension
1782 scripts)
1783 All user options must begin with a user description (user or username
1785 option) and follow all server descriptions and options.
1786 In the .fetchmailrc file, the 'envelope' string argument may be pre‐
1788 ceded by a whitespace-separated number. This number, if specified, is
1789 the number of such headers to skip over (that is, an argument of 1
1790 selects the second header of the given type). This is sometime useful
1791 for ignoring bogus envelope headers created by an ISP's local delivery
1792 agent or internal forwards (through mail inspection systems, for
1793 instance).
1794 Keywords Not Corresponding To Option Switches
1796 The 'folder' and 'smtphost' options (unlike their command-line equiva‐
1797 lents) can take a space- or comma-separated list of names following
1798 them.
1799 All options correspond to the obvious command-line arguments, except
1801 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1802 'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1803 'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1804 'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus', 'dropdeliv‐
1805 ered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle', and 'no
1806 envelope'.
1807 The 'via' option is for if you want to have more than one configuration
1809 pointing at the same site. If it is present, the string argument will
1810 be taken as the actual DNS name of the mailserver host to query. This
1811 will override the argument of poll, which can then simply be a distinct
1812 label for the configuration (e.g. what you would give on the command
1813 line to explicitly query this host).
1814 The 'interval' option (which takes a numeric argument) allows you to
1816 poll a server less frequently than the basic poll interval. If you say
1817 'interval N' the server this option is attached to will only be queried
1818 every N poll intervals.
1819 Singledrop vs. Multidrop options
1821 Please ensure you read the section titled THE USE AND ABUSE OF MUL‐
1822 TIDROP MAILBOXES if you intend to use multidrop mode.
1823 The 'is' or 'to' keywords associate the following local (client)
1825 name(s) (or server-name to client-name mappings separated by =) with
1826 the mailserver user name in the entry. If an is/to list has '*' as its
1827 last name, unrecognized names are simply passed through. Note that
1828 until fetchmail version 6.3.4 inclusively, these lists could only con‐
1829 tain local parts of user names (fetchmail would only look at the part
1830 before the @ sign). fetchmail versions 6.3.5 and newer support full
1831 addresses on the left hand side of these mappings, and they take prece‐
1832 dence over any 'localdomains', 'aka', 'via' or similar mappings.
1833 A single local name can be used to support redirecting your mail when
1835 your username on the client machine is different from your name on the
1836 mailserver. When there is only a single local name, mail is forwarded
1837 to that local username regardless of the message's Received, To, Cc,
1838 and Bcc headers. In this case, fetchmail never does DNS lookups.
1839 When there is more than one local name (or name mapping), fetchmail
1841 looks at the envelope header, if configured, and otherwise at the
1842 Received, To, Cc, and Bcc headers of retrieved mail (this is 'multidrop
1843 mode'). It looks for addresses with hostname parts that match your
1844 poll name or your 'via', 'aka' or 'localdomains' options, and usually
1845 also for hostname parts which DNS tells it are aliases of the
1846 mailserver. See the discussion of 'dns', 'checkalias', 'localdomains',
1847 and 'aka' for details on how matching addresses are handled.
1848 If fetchmail cannot match any mailserver usernames or localdomain
1850 addresses, the mail will be bounced. Normally it will be bounced to
1851 the sender, but if the 'bouncemail' global option is off, the mail will
1852 go to the local postmaster instead. (see the 'postmaster' global
1853 option). See also BUGS.
1854 The 'dns' option (normally on) controls the way addresses from mul‐
1856 tidrop mailboxes are checked. On, it enables logic to check each host
1857 address that does not match an 'aka' or 'localdomains' declaration by
1858 looking it up with DNS. When a mailserver username is recognized
1859 attached to a matching hostname part, its local mapping is added to the
1860 list of local recipients.
1861 The 'checkalias' option (normally off) extends the lookups performed by
1863 the 'dns' keyword in multidrop mode, providing a way to cope with
1864 remote MTAs that identify themselves using their canonical name, while
1865 they're polled using an alias. When such a server is polled, checks to
1866 extract the envelope address fail, and fetchmail reverts to delivery
1867 using the To/Cc/Bcc headers (See below 'Header vs. Envelope
1868 addresses'). Specifying this option instructs fetchmail to retrieve
1869 all the IP addresses associated with both the poll name and the name
1870 used by the remote MTA and to do a comparison of the IP addresses.
1871 This comes in handy in situations where the remote server undergoes
1872 frequent canonical name changes, that would otherwise require modifica‐
1873 tions to the rcfile. 'checkalias' has no effect if 'no dns' is speci‐
1874 fied in the rcfile.
1875 The 'aka' option is for use with multidrop mailboxes. It allows you to
1877 pre-declare a list of DNS aliases for a server. This is an optimiza‐
1878 tion hack that allows you to trade space for speed. When fetchmail,
1879 while processing a multidrop mailbox, grovels through message headers
1880 looking for names of the mailserver, pre-declaring common ones can save
1881 it from having to do DNS lookups. Note: the names you give as argu‐
1882 ments to 'aka' are matched as suffixes -- if you specify (say) 'aka
1883 netaxs.com', this will match not just a hostname netaxs.com, but any
1884 hostname that ends with '.netaxs.com'; such as (say) pop3.netaxs.com
1885 and mail.netaxs.com.
1886 The 'localdomains' option allows you to declare a list of domains which
1888 fetchmail should consider local. When fetchmail is parsing address
1889 lines in multidrop modes, and a trailing segment of a host name matches
1890 a declared local domain, that address is passed through to the listener
1891 or MDA unaltered (local-name mappings are not applied).
1892 If you are using 'localdomains', you may also need to specify 'no enve‐
1894 lope', which disables fetchmail's normal attempt to deduce an envelope
1895 address from the Received line or X-Envelope-To header or whatever
1896 header has been previously set by 'envelope'. If you set 'no envelope'
1897 in the defaults entry it is possible to undo that in individual entries
1898 by using 'envelope <string>'. As a special case, 'envelope "Received"'
1899 restores the default parsing of Received lines.
1900 The password option requires a string argument, which is the password
1902 to be used with the entry's server.
1903 The 'preconnect' keyword allows you to specify a shell command to be
1905 executed just before each time fetchmail establishes a mailserver con‐
1906 nection. This may be useful if you are attempting to set up secure POP
1907 connections with the aid of ssh(1). If the command returns a nonzero
1908 status, the poll of that mailserver will be aborted.
1909 Similarly, the 'postconnect' keyword similarly allows you to specify a
1911 shell command to be executed just after each time a mailserver connec‐
1912 tion is taken down.
1913 The 'forcecr' option controls whether lines terminated by LF only are
1915 given CRLF termination before forwarding. Strictly speaking RFC821
1916 requires this, but few MTAs enforce the requirement it so this option
1917 is normally off (only one such MTA, qmail, is in significant use at
1918 time of writing).
1919 The 'stripcr' option controls whether carriage returns are stripped out
1921 of retrieved mail before it is forwarded. It is normally not necessary
1922 to set this, because it defaults to 'on' (CR stripping enabled) when
1923 there is an MDA declared but 'off' (CR stripping disabled) when for‐
1924 warding is via SMTP. If 'stripcr' and 'forcecr' are both on, 'stripcr'
1925 will override.
1926 The 'pass8bits' option exists to cope with Microsoft mail programs that
1928 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1929 this option off (the default) and such a header present, fetchmail
1930 declares BODY=7BIT to an ESMTP-capable listener; this causes problems
1931 for messages actually using 8-bit ISO or KOI-8 character sets, which
1932 will be garbled by having the high bits of all characters stripped. If
1933 'pass8bits' is on, fetchmail is forced to declare BODY=8BITMIME to any
1934 ESMTP-capable listener. If the listener is 8-bit-clean (as all the
1935 major ones now are) the right thing will probably result.
1936 The 'dropstatus' option controls whether nonempty Status and X-Mozilla-
1938 Status lines are retained in fetched mail (the default) or discarded.
1939 Retaining them allows your MUA to see what messages (if any) were
1940 marked seen on the server. On the other hand, it can confuse some new-
1941 mail notifiers, which assume that anything with a Status line in it has
1942 been seen. (Note: the empty Status lines inserted by some buggy POP
1943 servers are unconditionally discarded.)
1944 The 'dropdelivered' option controls whether Delivered-To headers will
1946 be kept in fetched mail (the default) or discarded. These headers are
1947 added by Qmail and Postfix mailservers in order to avoid mail loops but
1948 may get in your way if you try to "mirror" a mailserver within the same
1949 domain. Use with caution.
1950 The 'mimedecode' option controls whether MIME messages using the
1952 quoted-printable encoding are automatically converted into pure 8-bit
1953 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean lis‐
1954 tener (that includes all of the major MTAs like sendmail), then this
1955 will automatically convert quoted-printable message headers and data
1956 into 8-bit data, making it easier to understand when reading mail. If
1957 your e-mail programs know how to deal with MIME messages, then this
1958 option is not needed. The mimedecode option is off by default, because
1959 doing RFC2047 conversion on headers throws away character-set informa‐
1960 tion and can lead to bad results if the encoding of the headers differs
1961 from the body encoding.
1962 The 'idle' option is intended to be used with IMAP servers supporting
1964 the RFC2177 IDLE command extension, but does not strictly require it.
1965 If it is enabled, and fetchmail detects that IDLE is supported, an IDLE
1966 will be issued at the end of each poll. This will tell the IMAP server
1967 to hold the connection open and notify the client when new mail is
1968 available. If IDLE is not supported, fetchmail will simulate it by
1969 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1970 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1971 sequences. On the other hand, an IDLE connection will eat almost all of
1972 your fetchmail's time, because it will never drop the connection and
1973 allow other polls to occur unless the server times out the IDLE. It
1974 also doesn't work with multiple folders; only the first folder will
1975 ever be polled.
1976 The 'properties' option is an extension mechanism. It takes a string
1979 argument, which is ignored by fetchmail itself. The string argument
1980 may be used to store configuration information for scripts which
1981 require it. In particular, the output of '--configdump' option will
1982 make properties associated with a user entry readily available to a
1983 Python script.
1984 Miscellaneous Run Control Options
1986 The words 'here' and 'there' have useful English-like significance.
1987 Normally 'user eric is esr' would mean that mail for the remote user
1988 'eric' is to be delivered to 'esr', but you can make this clearer by
1989 saying 'user eric there is esr here', or reverse it by saying 'user esr
1990 here is eric there'
1991 Legal protocol identifiers for use with the 'protocol' keyword are:
1993 auto (or AUTO) (legacy, to be removed from future release)
1995 pop2 (or POP2) (legacy, to be removed from future release)
1996 pop3 (or POP3)
1997 sdps (or SDPS)
1998 imap (or IMAP)
1999 apop (or APOP)
2000 kpop (or KPOP)
2001 Legal authentication types are 'any', 'password', 'kerberos', 'ker‐
2004 beros_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn' (only
2005 for POP3), 'ntlm', 'ssh', 'external' (only IMAP). The 'password' type
2006 specifies authentication by normal transmission of a password (the
2007 password may be plain text or subject to protocol-specific encryption
2008 as in CRAM-MD5); 'kerberos' tells fetchmail to try to get a Kerberos
2009 ticket at the start of each query instead, and send an arbitrary string
2010 as the password; and 'gssapi' tells fetchmail to use GSSAPI authentica‐
2011 tion. See the description of the 'auth' keyword for more.
2012 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
2014 authentication. These defaults may be overridden by later options.
2015 There are some global option statements: 'set logfile' followed by a
2017 string sets the same global specified by --logfile. A command-line
2018 --logfile option will override this. Note that --logfile is only effec‐
2019 tive if fetchmail detaches itself from the terminal and the logfile
2020 already exists before fetchmail is run, and it overrides --syslog in
2021 this case. Also, 'set daemon' sets the poll interval as --daemon does.
2022 This can be overridden by a command-line --daemon option; in particular
2023 --daemon 0 can be used to force foreground operation. The 'set postmas‐
2024 ter' statement sets the address to which multidrop mail defaults if
2025 there are no local matches. Finally, 'set syslog' sends log messages
2026 to syslogd(8).
2027
2030 Fetchmail crashing
2031 There are various ways in that fetchmail may "crash", i. e. stop opera‐
2032 tion suddenly and unexpectedly. A "crash" usually refers to an error
2033 condition that the software did not handle by itself. A well-known
2034 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
2035 just "segfault" for short. These can be caused by hardware or by soft‐
2036 ware problems. Software-induced segfaults can usually be reproduced
2037 easily and in the same place, whereas hardware-induced segfaults can go
2038 away if the computer is rebooted, or powered off for a few hours, and
2039 can happen in random locations even if you use the software the same
2040 way.
2041 For solving hardware-induced segfaults, find the faulty component and
2043 repair or replace it. The Sig11 FAQ ⟨http://www.bitwizard.nl/sig11/⟩
2044 may help you with details.
2045 For solving software-induced segfaults, the developers may need a
2047 "stack backtrace".
2048 Enabling fetchmail core dumps
2051 By default, fetchmail suppresses core dumps as these might contain
2052 passwords and other sensitive information. For debugging fetchmail
2053 crashes, obtaining a "stack backtrace" from a core dump is often the
2054 quickest way to solve the problem, and when posting your problem on a
2055 mailing list, the developers may ask you for a "backtrace".
2056 1. To get useful backtraces, fetchmail needs to be installed without
2058 getting stripped of its compilation symbols. Unfortunately, most
2059 binary packages that are installed are stripped, and core files from
2060 symbol-stripped programs are worthless. So you may need to recompile
2061 fetchmail. On many systems, you can type
2062 file `which fetchmail`
2064 to find out if fetchmail was symbol-stripped or not. If yours was
2066 unstripped, fine, proceed, if it was stripped, you need to recompile
2067 the source code first. You do not usually need to install fetchmail in
2068 order to debug it.
2069 2. The shell environment that starts fetchmail needs to enable core
2071 dumps. The key is the "maximum core (file) size" that can usually be
2072 configured with a tool named "limit" or "ulimit". See the documentation
2073 for your shell for details. In the popular bash shell, "ulimit -Sc
2074 unlimited" will allow the core dump.
2075 3. You need to tell fetchmail, too, to allow core dumps. To do this,
2077 run fetchmail with the -d0 -v options. It is often easier to also add
2078 --nosyslog -N as well.
2079 Finally, you need to reproduce the crash. You can just start fetchmail
2081 from the directory where you compiled it by typing ./fetchmail, so the
2082 complete command line will start with ./fetchmail -Nvd0 --nosyslog and
2083 perhaps list your other options.
2084 After the crash, run your debugger to obtain the core dump. The debug‐
2086 ger will often be GNU GDB, you can then type (adjust paths as neces‐
2087 sary) gdb ./fetchmail fetchmail.core and then, after GDB has started up
2088 and read all its files, type backtrace full, save the output (copy &
2089 paste will do, the backtrace will be read by a human) and then type
2090 quit to leave gdb. Note: on some systems, the core files have differ‐
2091 ent names, they might contain a number instead of the program name, or
2092 number and name, but it will usually have "core" as part of their name.
2093
2096 When trying to determine the originating address of a message, fetch‐
2097 mail looks through headers in the following order:
2098 Return-Path:
2100 Resent-Sender: (ignored if it doesn't contain an @ or !)
2101 Sender: (ignored if it doesn't contain an @ or !)
2102 Resent-From:
2103 From:
2104 Reply-To:
2105 Apparently-From:
2106 The originating address is used for logging, and to set the MAIL FROM
2108 address when forwarding to SMTP. This order is intended to cope grace‐
2109 fully with receiving mailing list messages in multidrop mode. The
2110 intent is that if a local address doesn't exist, the bounce message
2111 won't be returned blindly to the author or to the list itself, but
2112 rather to the list manager (which is less annoying).
2113 In multidrop mode, destination headers are processed as follows: First,
2115 fetchmail looks for the header specified by the 'envelope' option in
2116 order to determine the local recipient address. If the mail is
2117 addressed to more than one recipient, the Received line won't contain
2118 any information regarding recipient addresses.
2119 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2121 lines. If they exist, they should contain the final recipients and
2122 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
2123 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2124 looked for. (The presence of a Resent-To: is taken to imply that the
2125 person referred by the To: address has already received the original
2126 copy of the mail.)
2127
2130 Note that although there are password declarations in a good many of
2131 the examples below, this is mainly for illustrative purposes. We rec‐
2132 ommend stashing account/password pairs in your $HOME/.netrc file, where
2133 they can be used not just by fetchmail but by ftp(1) and other pro‐
2134 grams.
2135 The basic format is:
2137 poll SERVERNAME protocol PROTOCOL username NAME password PASS‐
2140 WORD
2141 Example:
2144 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2147 Or, using some abbreviations:
2150 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2153 Multiple servers may be listed:
2156 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2159 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2160 Here's the same version with more whitespace and some noise words:
2163 poll pop.provider.net proto pop3
2166 user "jsmith", with password secret1, is "jsmith" here;
2167 poll other.provider.net proto pop2:
2168 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2169 If you need to include whitespace in a parameter string or start the
2172 latter with a number, enclose the string in double quotes. Thus:
2173 poll mail.provider.net with proto pop3:
2176 user "jsmith" there has password "4u but u can't krak this"
2177 is jws here and wants mda "/bin/mail"
2178 You may have an initial server description headed by the keyword
2181 'defaults' instead of 'poll' followed by a name. Such a record is
2182 interpreted as defaults for all queries to use. It may be overwritten
2183 by individual server descriptions. So, you could write:
2184 defaults proto pop3
2187 user "jsmith"
2188 poll pop.provider.net
2189 pass "secret1"
2190 poll mail.provider.net
2191 user "jjsmith" there has password "secret2"
2192 It's possible to specify more than one user per server. The 'user'
2195 keyword leads off a user description, and every user specification in a
2196 multi-user entry must include it. Here's an example:
2197 poll pop.provider.net proto pop3 port 3111
2200 user "jsmith" with pass "secret1" is "smith" here
2201 user jones with pass "secret2" is "jjones" here keep
2202 This associates the local username 'smith' with the pop.provider.net
2205 username 'jsmith' and the local username 'jjones' with the
2206 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2207 server after download.
2208 Here's what a simple retrieval configuration for a multidrop mailbox
2211 looks like:
2212 poll pop.provider.net:
2215 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2216 This says that the mailbox of account 'maildrop' on the server is a
2219 multidrop box, and that messages in it should be parsed for the server
2220 user names 'golux', 'hurkle', and 'snark'. It further specifies that
2221 'golux' and 'snark' have the same name on the client as on the server,
2222 but mail for server user 'hurkle' should be delivered to client user
2223 'happy'.
2224 Note that fetchmail, until version 6.3.4, did NOT allow full
2227 user@domain specifications here, these would never match. Fetchmail
2228 6.3.5 and newer support user@domain specifications on the left-hand
2229 side of a user mapping.
2230 Here's an example of another kind of multidrop connection:
2233 poll pop.provider.net localdomains loonytoons.org toons.org
2236 envelope X-Envelope-To
2237 user maildrop with pass secret1 to * here
2238 This also says that the mailbox of account 'maildrop' on the server is
2241 a multidrop box. It tells fetchmail that any address in the loony‐
2242 toons.org or toons.org domains (including sub-domain addresses like
2243 'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2244 listener without modification. Be careful of mail loops if you do
2245 this!
2246 Here's an example configuration using ssh and the plugin option. The
2249 queries are made directly on the stdin and stdout of imapd via ssh.
2250 Note that in this setup, IMAP authentication can be skipped.
2251 poll mailhost.net with proto imap:
2254 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2255 user esr is esr here
2256
2259 Use the multiple-local-recipients feature with caution -- it can bite.
2260 All multidrop features are ineffective in ETRN and ODMR modes.
2261 Also, note that in multidrop mode duplicate mails are suppressed. A
2263 piece of mail is considered duplicate if it has the same message-ID as
2264 the message immediately preceding and more than one addressee. Such
2265 runs of messages may be generated when copies of a message addressed to
2266 multiple users are delivered to a multidrop box.
2267 Header vs. Envelope addresses
2270 The fundamental problem is that by having your mailserver toss several
2271 peoples' mail in a single maildrop box, you may have thrown away poten‐
2272 tially vital information about who each piece of mail was actually
2273 addressed to (the 'envelope address', as opposed to the header
2274 addresses in the RFC822 To/Cc headers - the Bcc is not available at the
2275 receiving end). This 'envelope address' is the address you need in
2276 order to reroute mail properly.
2277 Sometimes fetchmail can deduce the envelope address. If the mailserver
2279 MTA is sendmail and the item of mail had just one recipient, the MTA
2280 will have written a 'by/for' clause that gives the envelope addressee
2281 into its Received header. But this doesn't work reliably for other
2282 MTAs, nor if there is more than one recipient. By default, fetchmail
2283 looks for envelope addresses in these lines; you can restore this
2284 default with -E "Received" or 'envelope Received'.
2285 As a better alternative, some SMTP listeners and/or mail servers insert
2287 a header in each message containing a copy of the envelope addresses.
2288 This header (when it exists) is often 'X-Original-To', 'Delivered-To'
2289 or 'X-Envelope-To'. Fetchmail's assumption about this can be changed
2290 with the -E or 'envelope' option. Note that writing an envelope header
2291 of this kind exposes the names of recipients (including blind-copy
2292 recipients) to all receivers of the messages, so the upstream must
2293 store one copy of the message per recipient to avoid becoming a privacy
2294 problem.
2295 Postfix, since version 2.0, writes an X-Original-To: header which con‐
2297 tains a copy of the envelope as it was received.
2298 Qmail and Postfix generally write a 'Delivered-To' header upon deliver‐
2300 ing the message to the mail spool and use it to avoid mail loops.
2301 Qmail virtual domains however will prefix the user name with a string
2302 that normally matches the user's domain. To remove this prefix you can
2303 use the -Q or 'qvirtual' option.
2304 Sometimes, unfortunately, neither of these methods works. That is the
2306 point when you should contact your ISP and ask them to provide such an
2307 envelope header, and you should not use multidrop in this situation.
2308 When they all fail, fetchmail must fall back on the contents of To/Cc
2309 headers (Bcc headers are not available - see below) to try to determine
2310 recipient addressees -- and these are unreliable. In particular, mail‐
2311 ing-list software often ships mail with only the list broadcast address
2312 in the To header.
2313 Note that a future version of fetchmail may remove To/Cc parsing!
2315 When fetchmail cannot deduce a recipient address that is local, and the
2317 intended recipient address was anyone other than fetchmail's invoking
2318 user, mail will get lost. This is what makes the multidrop feature
2319 risky without proper envelope information.
2320 A related problem is that when you blind-copy a mail message, the Bcc
2322 information is carried only as envelope address (it's removed from the
2323 headers by the sending mail server, so fetchmail can see it only if
2324 there is an X-Envelope-To header). Thus, blind-copying to someone who
2325 gets mail over a fetchmail multidrop link will fail unless the the
2326 mailserver host routinely writes X-Envelope-To or an equivalent header
2327 into messages in your maildrop.
2328 In conclusion, mailing lists and Bcc'd mail can only work if the server
2330 you're fetching from
2331 (1) stores one copy of the message per recipient in your domain and
2333 (2) records the envelope information in a special header (X-Origi‐
2335 nal-To, Delivered-To, X-Envelope-To).
2336 Good Ways To Use Multidrop Mailboxes
2339 Multiple local names can be used to administer a mailing list from the
2340 client side of a fetchmail collection. Suppose your name is 'esr', and
2341 you want to both pick up your own mail and maintain a mailing list
2342 called (say) "fetchmail-friends", and you want to keep the alias list
2343 on your client machine.
2344 On your server, you can alias 'fetchmail-friends' to 'esr'; then, in
2346 your .fetchmailrc, declare 'to esr fetchmail-friends here'. Then, when
2347 mail including 'fetchmail-friends' as a local address gets fetched, the
2348 list name will be appended to the list of recipients your SMTP listener
2349 sees. Therefore it will undergo alias expansion locally. Be sure to
2350 include 'esr' in the local alias expansion of fetchmail-friends, or
2351 you'll never see mail sent only to the list. Also be sure that your
2352 listener has the "me-too" option set (sendmail's -oXm command-line
2353 option or OXm declaration) so your name isn't removed from alias expan‐
2354 sions in messages you send.
2355 This trick is not without its problems, however. You'll begin to see
2357 this when a message comes in that is addressed only to a mailing list
2358 you do not have declared as a local name. Each such message will fea‐
2359 ture an 'X-Fetchmail-Warning' header which is generated because fetch‐
2360 mail cannot find a valid local name in the recipient addresses. Such
2361 messages default (as was described above) to being sent to the local
2362 user running fetchmail, but the program has no way to know that that's
2363 actually the right thing.
2364 Bad Ways To Abuse Multidrop Mailboxes
2367 Multidrop mailboxes and fetchmail serving multiple users in daemon mode
2368 do not mix. The problem, again, is mail from mailing lists, which typ‐
2369 ically does not have an individual recipient address on it. Unless
2370 fetchmail can deduce an envelope address, such mail will only go to the
2371 account running fetchmail (probably root). Also, blind-copied users
2372 are very likely never to see their mail at all.
2373 If you're tempted to use fetchmail to retrieve mail for multiple users
2375 from a single mail drop via POP or IMAP, think again (and reread the
2376 section on header and envelope addresses above). It would be smarter
2377 to just let the mail sit in the mailserver's queue and use fetchmail's
2378 ETRN or ODMR modes to trigger SMTP sends periodically (of course, this
2379 means you have to poll more frequently than the mailserver's expiry
2380 period). If you can't arrange this, try setting up a UUCP feed.
2381 If you absolutely must use multidrop for this purpose, make sure your
2383 mailserver writes an envelope-address header that fetchmail can see.
2384 Otherwise you will lose mail and it will come back to haunt you.
2385 Speeding Up Multidrop Checking
2388 Normally, when multiple users are declared fetchmail extracts recipient
2389 addresses as described above and checks each host part with DNS to see
2390 if it's an alias of the mailserver. If so, the name mappings described
2391 in the "to ... here" declaration are done and the mail locally deliv‐
2392 ered.
2393 This is a convenient but also slow method. To speed it up, pre-declare
2395 mailserver aliases with 'aka'; these are checked before DNS lookups are
2396 done. If you're certain your aka list contains all DNS aliases of the
2397 mailserver (and all MX names pointing at it - note this may change in a
2398 future version) you can declare 'no dns' to suppress DNS lookups
2399 entirely and only match against the aka list.
2400
2403 Support for socks4/5 is a compile time configuration option. Once com‐
2404 piled in, fetchmail will always use the socks libraries and configura‐
2405 tion on your system, there are no run-time switches in fetchmail - but
2406 you can still configure SOCKS: you can specify which SOCKS configura‐
2407 tion file is used in the SOCKS_CONF environment variable.
2408 For instance, if you wanted to bypass the SOCKS proxy altogether and
2410 have fetchmail connect directly, you could just pass
2411 SOCKS_CONF=/dev/null in the environment, for example (add your usual
2412 command line options - if any - to the end of this line):
2413 env SOCKS_CONF=/dev/null fetchmail
2415
2418 To facilitate the use of fetchmail in shell scripts, an exit status
2419 code is returned to give an indication of what occurred during a given
2420 connection.
2421 The exit codes returned by fetchmail are as follows:
2423 0 One or more messages were successfully retrieved (or, if the -c
2425 option was selected, were found waiting but not retrieved).
2426 1 There was no mail awaiting retrieval. (There may have been old
2428 mail still on the server but not selected for retrieval.) If you
2429 do not want "no mail" to be an error condition (for instance,
2430 for cron jobs), use a POSIX-compliant shell and add
2431 || [ $? -eq 1 ]
2433 to the end of the fetchmail command line, note that this leaves
2435 0 untouched, maps 1 to 0, and maps all other codes to 1. See
2436 also item #C8 in the FAQ.
2437 2 An error was encountered when attempting to open a socket to
2439 retrieve mail. If you don't know what a socket is, don't worry
2440 about it -- just treat this as an 'unrecoverable error'. This
2441 error can also be because a protocol fetchmail wants to use is
2442 not listed in /etc/services.
2443 3 The user authentication step failed. This usually means that a
2445 bad user-id, password, or APOP id was specified. Or it may mean
2446 that you tried to run fetchmail under circumstances where it did
2447 not have standard input attached to a terminal and could not
2448 prompt for a missing password.
2449 4 Some sort of fatal protocol error was detected.
2451 5 There was a syntax error in the arguments to fetchmail, or a
2453 pre- or post-connect command failed.
2454 6 The run control file had bad permissions.
2456 7 There was an error condition reported by the server. Can also
2458 fire if fetchmail timed out while waiting for the server.
2459 8 Client-side exclusion error. This means fetchmail either found
2461 another copy of itself already running, or failed in such a way
2462 that it isn't sure whether another copy is running.
2463 9 The user authentication step failed because the server responded
2465 "lock busy". Try again after a brief pause! This error is not
2466 implemented for all protocols, nor for all servers. If not
2467 implemented for your server, "3" will be returned instead, see
2468 above. May be returned when talking to qpopper or other servers
2469 that can respond with "lock busy" or some similar text contain‐
2470 ing the word "lock".
2471 10 The fetchmail run failed while trying to do an SMTP port open or
2473 transaction.
2474 11 Fatal DNS error. Fetchmail encountered an error while perform‐
2476 ing a DNS lookup at startup and could not proceed.
2477 12 BSMTP batch file could not be opened.
2479 13 Poll terminated by a fetch limit (see the --fetchlimit option).
2481 14 Server busy indication.
2483 23 Internal error. You should see a message on standard error with
2485 details.
2486 24 - 26, 28, 29
2488 These are internal codes and should not appear externally.
2489 When fetchmail queries more than one host, return status is 0 if any
2491 query successfully retrieved mail. Otherwise the returned error status
2492 is that of the last host queried.
2493
2496 ~/.fetchmailrc
2497 default run control file
2498 ~/.fetchids
2500 default location of file recording last message UIDs seen per
2501 host.
2502 ~/.fetchmail.pid
2504 lock file to help prevent concurrent runs (non-root mode).
2505 ~/.netrc
2507 your FTP run control file, which (if present) will be searched for
2508 passwords as a last resort before prompting for one interactively.
2509 /var/run/fetchmail.pid
2511 lock file to help prevent concurrent runs (root mode, Linux sys‐
2512 tems).
2513 /etc/fetchmail.pid
2515 lock file to help prevent concurrent runs (root mode, systems
2516 without /var/run).
2517
2520 FETCHMAILHOME
2521 If this environment variable is set to a valid and existing
2522 directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
2523 (the dot is missing in this case), $FETCHMAILHOME/.fetchids and
2524 $FETCHMAILHOME/.fetchmail.pid rather than from the user's home
2525 directory. The .netrc file is always looked for in the the
2526 invoking user's home directory regardless of FETCHMAILHOME's
2527 setting.
2528 FETCHMAILUSER
2531 If this environment variable is set, it is used as the name of
2532 the calling user (default local name) for purposes such as mail‐
2533 ing error notifications. Otherwise, if either the LOGNAME or
2534 USER variable is correctly set (e.g. the corresponding UID
2535 matches the session user ID) then that name is used as the
2536 default local name. Otherwise getpwuid(3) must be able to
2537 retrieve a password entry for the session ID (this elaborate
2538 logic is designed to handle the case of multiple names per
2539 userid gracefully).
2540 FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS
2543 (since v6.3.17): If this environment variable is set and not
2544 empty, fetchmail will always load the default X.509 trusted cer‐
2545 tificate locations for SSL/TLS CA certificates, even if
2546 --sslcertfile and --sslcertpath are given. The latter locations
2547 take precedence over the system default locations. This is use‐
2548 ful in case there are broken certificates in the system directo‐
2549 ries and the user has no administrator privileges to remedy the
2550 problem.
2551 HOME_ETC
2554 If the HOME_ETC variable is set, fetchmail will read
2555 $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.
2556 If HOME_ETC and FETCHMAILHOME are both set, HOME_ETC will be
2558 ignored.
2559 SOCKS_CONF
2562 (only if SOCKS support is compiled in) this variable is used by
2563 the socks library to find out which configuration file it should
2564 read. Set this to /dev/null to bypass the SOCKS proxy.
2565
2568 If a fetchmail daemon is running as root, SIGUSR1 wakes it up from its
2569 sleep phase and forces a poll of all non-skipped servers. For compati‐
2570 bility reasons, SIGHUP can also be used in 6.3.X but may not be avail‐
2571 able in future fetchmail versions.
2572 If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake
2574 it (this is so SIGHUP due to logout can retain the default action of
2575 killing it).
2576 Running fetchmail in foreground while a background fetchmail is running
2578 will do whichever of these is appropriate to wake it up.
2579
2582 Please check the NEWS file that shipped with fetchmail for more known
2583 bugs than those listed here.
2584 Fetchmail cannot handle user names that contain blanks after a "@"
2586 character, for instance "demonstr@ti on". These are rather uncommon and
2587 only hurt when using UID-based --keep setups, so the 6.3.X versions of
2588 fetchmail won't be fixed.
2589 The assumptions that the DNS and in particular the checkalias options
2591 make are not often sustainable. For instance, it has become uncommon
2592 for an MX server to be a POP3 or IMAP server at the same time. There‐
2593 fore the MX lookups may go away in a future release.
2594 The mda and plugin options interact badly. In order to collect error
2596 status from the MDA, fetchmail has to change its normal signal handling
2597 so that dead plugin processes don't get reaped until the end of the
2598 poll cycle. This can cause resource starvation if too many zombies
2599 accumulate. So either don't deliver to a MDA using plugins or risk
2600 being overrun by an army of undead.
2601 The --interface option does not support IPv6 and it is doubtful if it
2603 ever will, since there is no portable way to query interface IPv6
2604 addresses.
2605 The RFC822 address parser used in multidrop mode chokes on some
2607 @-addresses that are technically legal but bizarre. Strange uses of
2608 quoting and embedded comments are likely to confuse it.
2609 In a message with multiple envelope headers, only the last one pro‐
2611 cessed will be visible to fetchmail.
2612 Use of some of these protocols requires that the program send unen‐
2614 crypted passwords over the TCP/IP connection to the mailserver. This
2615 creates a risk that name/password pairs might be snaffled with a packet
2616 sniffer or more sophisticated monitoring software. Under Linux and
2617 FreeBSD, the --interface option can be used to restrict polling to
2618 availability of a specific interface device with a specific local or
2619 remote IP address, but snooping is still possible if (a) either host
2620 has a network device that can be opened in promiscuous mode, or (b) the
2621 intervening network link can be tapped. We recommend the use of ssh(1)
2622 tunnelling to not only shroud your passwords but encrypt the entire
2623 conversation.
2624 Use of the %F or %T escapes in an mda option could open a security
2626 hole, because they pass text manipulable by an attacker to a shell com‐
2627 mand. Potential shell characters are replaced by '_' before execution.
2628 The hole is further reduced by the fact that fetchmail temporarily dis‐
2629 cards any suid privileges it may have while running the MDA. For maxi‐
2630 mum safety, however, don't use an mda command containing %F or %T when
2631 fetchmail is run from the root account itself.
2632 Fetchmail's method of sending bounces due to errors or spam-blocking
2634 and spam bounces requires that port 25 of localhost be available for
2635 sending mail via SMTP.
2636 If you modify ~/.fetchmailrc while a background instance is running and
2638 break the syntax, the background instance will die silently. Unfortu‐
2639 nately, it can't die noisily because we don't yet know whether syslog
2640 should be enabled. On some systems, fetchmail dies quietly even if
2641 there is no syntax error; this seems to have something to do with buggy
2642 terminal ioctl code in the kernel.
2643 The -f - option (reading a configuration from stdin) is incompatible
2645 with the plugin option.
2646 The 'principal' option only handles Kerberos IV, not V.
2648 Interactively entered passwords are truncated after 63 characters. If
2650 you really need to use a longer password, you will have to use a con‐
2651 figuration file.
2652 A backslash as the last character of a configuration file will be
2654 flagged as a syntax error rather than ignored.
2655 The BSMTP error handling is virtually nonexistent and may leave broken
2657 messages behind.
2658 Send comments, bug reports, gripes, and the like to the fetchmail-devel
2660 list ⟨fetchmail-devel@lists.berlios.de⟩
2661 An HTML FAQ ⟨http://fetchmail.berlios.de/fetchmail-FAQ.html⟩ is avail‐
2664 able at the fetchmail home page, it should also accompany your instal‐
2665 lation.
2666
2669 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2670 major assistance from Sunil Shetye (for code) and Rob MacGregor (for
2671 the mailing lists).
2672 Most of the code is from Eric S. Raymond ⟨esr@snark.thyrsus.com⟩ . Too
2674 many other people to name here have contributed code and patches.
2675 This program is descended from and replaces popclient, by Carl Harris
2677 ⟨ceharris@mal.com⟩ ; the internals have become quite different, but
2678 some of its interface design is directly traceable to that ancestral
2679 program.
2680 This manual page has been improved by Matthias Andree, R. Hannes Bein‐
2682 ert, and Héctor García.
2683
2686 README, README.SSL, README.SSL-SERVER, The Fetchmail FAQ ⟨http://
2687 www.fetchmail.info/fetchmail-FAQ.html⟩, mutt(1), elm(1), mail(1), send‐
2688 mail(8), popd(8), imapd(8), netrc(5).
2689 The fetchmail home page. ⟨http://fetchmail.berlios.de/⟩
2692 The maildrop home page. ⟨http://www.courier-mta.org/maildrop/⟩
2695
2698 Note that this list is just a collection of references and not a state‐
2699 ment as to the actual protocol conformance or requirements in fetch‐
2700 mail.
2701 SMTP/ESMTP:
2703 RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC
2704 1985, RFC 2554.
2705 mail:
2707 RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
2708 POP2:
2710 RFC 937
2711 POP3:
2713 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC
2714 1957, RFC 2195, RFC 2449.
2715 APOP:
2717 RFC 1939.
2718 RPOP:
2720 RFC 1081, RFC 1225.
2721 IMAP2/IMAP2BIS:
2723 RFC 1176, RFC 1732.
2724 IMAP4/IMAP4rev1:
2726 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC
2727 2177, RFC 2683.
2728 ETRN:
2730 RFC 1985.
2731 ODMR/ATRN:
2733 RFC 2645.
2734 OTP: RFC 1938.
2736 LMTP:
2738 RFC 2033.
2739 GSSAPI:
2741 RFC 1508.
2742 TLS: RFC 2595.
2744fetchmail fetchmail 6.3.17 fetchmail(1)