2 .\" ** The above line should force tbl to be used as a preprocessor **
4 .\" Manual page in man(7) format with tbl(1) macros for fetchmail
6 .\" For license terms, see the file COPYING in this directory.
10 fetchmail \- fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
13 \fBfetchmail\fR [\fIoption...\fR] [\fImailserver...\fR]
19 is a mail-retrieval and forwarding utility; it fetches mail from
20 remote mailservers and forwards it to your local (client) machine's
21 delivery system. You can then handle the retrieved mail using normal
22 mail user agents such as \fImutt\fR(1), \fIelm\fR(1) or \fIMail\fR(1).
23 The \fIfetchmail\fR utility can be run in a daemon mode to repeatedly
24 poll one or more systems at a specified interval.
28 program can gather mail from servers supporting any of the common
29 mail-retrieval protocols: POP2 (legacy, to be removed from future
30 release), POP3, IMAP2bis, IMAP4, and IMAP4rev1.
31 It can also use the ESMTP ETRN extension and ODMR. (The RFCs describing all
32 these protocols are listed at the end of this manual page.)
36 is primarily intended to be used over on-demand TCP/IP links (such as
37 SLIP or PPP connections), it may also be useful as a message transfer
38 agent for sites which refuse for security reasons to permit
39 (sender-initiated) SMTP transactions with sendmail.
43 is used with a POP or an IMAP server, it has two fundamental modes of
44 operation for each user account from which it retrieves mail:
45 \fIsingledrop\fR- and \fImultidrop\fR-mode. In singledrop-mode,
47 assumes that all messages in the user's account are intended for a single
48 recipient. An individual mail message will not be inspected for recipient
49 information, rather, the identity of the recipient will either default to
50 the local user currently executing \fIfetchmail\fR,
51 or else will need to be explicitly specified in the configuration file.
52 Singledrop-mode is used when the fetchmailrc configuration contains at
53 most a single local user specification for a given server account.
57 is not able to assume that there is only a single recipient, but rather
58 that the mail server account actually contains mail intended for any
59 number of different recipients. Therefore,
61 must attempt to deduce the proper "envelope recipient" from the mail
62 headers of each message. In this mode of operation
64 almost resembles an MTA, however it is important to note that neither
65 the POP nor IMAP protocols were intended for use in this fashion, and
66 hence envelope information is not directly available. Instead,
68 must resort to a process of informed guess-work in an attempt to
69 discover the true envelope recipient of a message. Even if this
70 information is present in the headers, the process can
71 be error-prone and is dependent upon the specific mail server used
72 for mail retrieval. Multidrop-mode is used when more than one local
73 user is specified for a particular server account in the configuration
74 file. Note that the forgoing discussion of singledrop- and
75 multidrop-modes does not apply to the ESMTP ETRN or ODMR retrieval
76 methods, since they are based upon the SMTP protocol which
77 specifically provides the envelope recipient to \fIfetchmail\fR.
79 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
80 port 25 on the machine it is running on (localhost), just as though it
81 were being passed in over a normal TCP/IP link. \fIfetchmail\fR provides
82 the SMTP server with an envelope recipient derived in the manner described
83 previously. The mail will then be
84 delivered locally via your system's MDA (Mail Delivery Agent, usually
85 \fIsendmail\fR(8) but your system may use a different one such
86 as \fIsmail\fR, \fImmdf\fR, \fIexim\fR, \fIpostfix\fR, or \fIqmail\fR). All the
87 delivery-control mechanisms (such as \fI.forward\fR files) normally
88 available through your system MDA and local delivery agents will
89 therefore work automatically.
91 If no port 25 listener is available, but your fetchmail configuration
92 was told about a reliable local MDA, it will use that MDA for local
97 is available, it will assist you in setting up and editing a
98 fetchmailrc configuration. It runs under the X window system and
99 requires that the language Python and the Tk toolkit be present on your
100 system. If you are first setting up fetchmail for single-user mode, it
101 is recommended that you use Novice mode. Expert mode provides complete
102 control of fetchmail configuration, including the multidrop features.
103 In either case, the 'Autoprobe' button will tell you the most capable
104 protocol a given mailserver supports, and warn you of potential problems
107 .SH GENERAL OPERATION
110 is controlled by command-line options and a run control file,
111 .IR ~/.fetchmailrc\fR ,
112 the syntax of which we describe in a later section (this file is what
113 the \fIfetchmailconf\fR program edits). Command-line options override
117 Each server name that you specify following the options on the
118 command line will be queried. If you don't specify any servers
119 on the command line, each 'poll' entry in your
121 file will be queried.
123 To facilitate the use of
125 in scripts and pipelines, it returns an appropriate exit code upon
126 termination -- see EXIT CODES below.
128 The following options modify the behavior of \fIfetchmail\fR. It is
129 seldom necessary to specify any of these once you have a
130 working \fI.fetchmailrc\fR file set up.
132 Almost all options have a corresponding keyword which can be used to
137 Some special options are not covered here, but are documented instead
138 in sections on AUTHENTICATION and DAEMON MODE which follow.
142 Displays the version information for your copy of
144 No mail fetch is performed.
145 Instead, for each server specified, all the option information
146 that would be computed if
148 were connecting to that server is displayed. Any non-printables in
149 passwords or other string names are shown as backslashed C-like
150 escape sequences. This option is useful for verifying that your
151 options are set the way you want them.
154 Return a status code to indicate whether there is mail waiting,
155 without actually fetching or deleting mail (see EXIT CODES below).
156 This option turns off daemon mode (in which it would be useless). It
157 doesn't play well with queries to multiple sites, and doesn't work
158 with ETRN or ODMR. It will return a false positive if you leave read but
159 undeleted mail in your server mailbox and your fetch protocol can't
160 tell kept messages from new ones. This means it will work with IMAP,
161 not work with POP2, and may occasionally flake out under POP3.
164 Silent mode. Suppresses all progress/status messages that are
165 normally echoed to standard output during a fetch (but does not
166 suppress actual error messages). The --verbose option overrides this.
169 Verbose mode. All control messages passed between
171 and the mailserver are echoed to stdout. Overrides --silent.
172 Doubling this option (-v -v) causes extra diagnostic information
178 Retrieve both old (seen) and new messages from the mailserver. The
179 default is to fetch only messages the server has not marked seen.
180 Under POP3, this option also forces the use of RETR rather than TOP.
181 Note that POP2 retrieval behaves as though --all is always on (see
182 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN
187 Keep retrieved messages on the remote mailserver. Normally, messages
188 are deleted from the folder on the mailserver after they have been retrieved.
191 option causes retrieved messages to remain in your folder on the
192 mailserver. This option does not work with ETRN or ODMR.
196 Delete retrieved messages from the remote mailserver. This
197 option forces retrieved mail to be deleted. It may be useful if
198 you have specified a default of \fBkeep\fR in your
199 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
202 POP3/IMAP only. This is a dangerous option and can cause mail loss when
203 used improperly. It deletes old (seen) messages from the mailserver
204 before retrieving new messages. Warning: This can cause mail loss if
205 you check your mail with other clients than fetchmail, and cause
206 fetchmail to delete a message it had never fetched before. Similarly, if
207 your local MTA hangs and fetchmail is aborted, the next time you run
208 fetchmail, it will delete mail that was never delivered to you. You
209 should probably not use this option in your configuration file. What you
210 probably want is the default setting: if you don't specify '-k', then
211 fetchmail will automatically delete messages after successful
212 delivery. This option does not work with ETRN and ODMR.
215 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
216 mailserver before retrieving new messages. The size limit should be
217 separately sepecified with the --limit option. This option does not
218 work with ETRN or ODMR.
219 .SS Protocol and Query Options
221 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
222 (Keyword: proto[col])
223 Specify the protocol to use when communicating with the remote
224 mailserver. If no protocol is specified, the default is AUTO.
226 may be one of the following:
229 Tries IMAP, POP3, and POP2 (skipping any of these for which support
230 has not been compiled in).
232 Post Office Protocol 2 (legacy, to be removed from future release)
234 Post Office Protocol 3
236 Use POP3 with old-fashioned MD5-challenge authentication.
238 Use POP3 with RPOP authentication.
240 Use POP3 with Kerberos V4 authentication on port 1109.
242 Use POP3 with Demon Internet's SDPS extensions.
244 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
246 Use the ESMTP ETRN option.
248 Use the the On-Demand Mail Relay ESMTP profile.
251 All these alternatives work in basically the same way (communicating
252 with standard server daemons to fetch mail already delivered to a
253 mailbox on the server) except ETRN and ODMR. The ETRN mode
254 allows you to ask a compliant ESMTP server (such as BSD sendmail at
255 release 8.8.0 or higher) to immediately open a sender-SMTP connection
256 to your client machine and begin forwarding any items addressed to
257 your client machine in the server's queue of undelivered mail. The
258 ODMR mode requires an ODMR-capable server and works similarly to
259 ETRN, except that it does not require the client machine to have
264 Force UIDL use (effective only with POP3). Force client-side tracking
265 of 'newness' of messages (UIDL stands for "unique ID listing" and is
266 described in RFC1939). Use with 'keep' to use a mailbox as a baby
267 news drop for a group of users. The fact that seen messages are skipped
268 is logged, unless error logging is done through syslog while running in
269 daemon mode. Note that fetchmail may automatically enable this option
270 depending on upstream server capabilities. Note also that this option
271 may be removed and forced enabled in a future fetchmail version.
274 .B \-\-service <servicename>
275 (Keyword: service) Since version 6.3.0.
276 The service option permits you to specify a service name to connect to.
277 You can specify a decimal port number here, if your services database
278 lacks the required service-port assignments. See the FAQ item R12 and
279 the \-\-ssl documentation for details. This replaces the older \-\-port
282 .B \-P <portnumber> | \-\-port <portnumber>
284 Obsolete version of \-\-service that does not take service names.
286 this option may be removed from a future version.
288 .B \-\-principal <principal>
290 The principal option permits you to specify a service principal for
291 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
294 .B \-t <seconds> | \-\-timeout <seconds>
296 The timeout option allows you to set a server-nonresponse
297 timeout in seconds. If a mailserver does not send a greeting message
298 or respond to commands for the given number of seconds,
299 \fIfetchmail\fR will hang up on it. Without such a timeout
300 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
301 down host. This would be particularly annoying for a \fIfetchmail\fR
302 running in background. There is a default timeout which fetchmail\~-V
303 will report. If a given connection receives too many timeouts in
304 succession, fetchmail will consider it wedged and stop retrying,
305 the calling user will be notified by email if this happens.
307 .B \-\-plugin <command>
308 (Keyword: plugin) The plugin option allows you to use an external
309 program to establish the TCP connection. This is useful if you want
310 to use socks, SSL, ssh, or need some special firewalling setup. The
311 program will be looked up in $PATH and can optionally be passed the
312 hostname and port as arguments using "%h" and "%p" respectively (note
313 that the interpolation logic is rather primitive, and these token must
314 be bounded by whitespace or beginning of string or end of string).
315 Fetchmail will write to the plugin's stdin and read from the plugin's
318 .B \-\-plugout <command>
320 Identical to the plugin option above, but this one is used for the SMTP
321 connections (which will probably not need it, so it has been separated
324 .B \-r <name> | \-\-folder <name>
326 Causes a specified non-default mail folder on the mailserver (or
327 comma-separated list of folders) to be retrieved. The syntax of the
328 folder name is server-dependent. This option is not available under
332 (Keyword: tracepolls)
333 Tell fetchmail to poll trace information in the form 'polling %s
334 account %s' to the Received line it generates, where the %s parts are
335 replaced by the user's remote name and the poll label (the Received
336 header also normally includes the server's true name). This can be
337 used to facilitate mail filtering based on the account it is being
342 Causes the connection to the mail server to be encrypted via SSL. Connect
343 to the server using the specified base protocol over a connection secured
344 by SSL. SSL support must be present at the server.
346 If no port is specified, the connection is attempted to the well known
347 port of the SSL version of the base protocol. This is generally a
348 different port than the port used by the base protocol. For IMAP, this
349 is port 143 for the clear protocol and port 993 for the SSL secured
350 protocol, for POP3, it is port 110 for the cleartext and port 995 for
351 the encrypted variant.
353 If your system lacks the corresponding entries from /etc/services, see
354 the \-\-service option and specify the numeric port number as given in
355 the previous paragraph (unless your ISP had directed you to different
356 ports, which is uncommon however).
358 .B \-\-sslcert <name>
360 Specifies the file name of the client side public SSL certificate. Some
361 SSL encrypted servers may require client side keys and certificates for
362 authentication. In most cases, this is optional. This specifies
363 the location of the public key certificate to be presented to the server
364 at the time the SSL session is established. It is not required (but may
365 be provided) if the server does not require it. Some servers may
366 require it, some servers may request it but not require it, and some
367 servers may not request it at all. It may be the same file
368 as the private key (combined key and certificate file) but this is not
373 Specifies the file name of the client side private SSL key. Some SSL
374 encrypted servers may require client side keys and certificates for
375 authentication. In most cases, this is optional. This specifies
376 the location of the private key used to sign transactions with the server
377 at the time the SSL session is established. It is not required (but may
378 be provided) if the server does not require it. Some servers may
379 require it, some servers may request it but not require it, and some
380 servers may not request it at all. It may be the same file
381 as the public key (combined key and certificate file) but this is not
382 recommended. If a password is required to unlock the key, it will be
383 prompted for at the time just prior to establishing the session to the
384 server. This can cause some complications in daemon mode.
386 .B \-\-sslproto <name>
388 Forces an SSL protocol. Possible values are '\fBssl2\fR',
389 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
390 handshake does not work for your server. To defeat automatic TLSv1
391 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
392 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
397 Causes fetchmail to strictly check the server certificate against a set of
398 local trusted certificates (see the \fBsslcertpath\fR option). If the server
399 certificate is not signed by one of the trusted ones (directly or indirectly),
400 the SSL connection will fail. This checking should prevent man-in-the-middle
401 attacks against the SSL connection. Note that CRLs are seemingly not currently
402 supported by OpenSSL in certificate verification! Your system clock should
403 be reasonably accurate when using this option!
405 .B \-\-sslcertpath <directory>
406 (Keyword: sslcertpath)
407 Sets the directory fetchmail uses to look up local certificates. The default
408 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
409 it - every time you add or modify a certificate in the directory, you need
410 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
413 .B \-\-sslfingerprint <fingerprint>
414 (Keyword: sslfingerprint)
415 Specify the fingerprint of the server key (an MD5 hash of the key) in
416 hexadecimal notation with colons separating groups of two digits. The letter
417 hex digits must be in upper case. This is the default format OpenSSL uses,
418 and the one fetchmail uses to report the fingerprint when an SSL connection
419 is established. When this is specified, fetchmail will compare the server key
420 fingerprint with the given one, and the connection will fail if they do not
421 match. This can be used to prevent man-in-the-middle attacks.
423 To obtain the fingerprint of a certificate stored in the file cert.pem,
427 openssl x509 -in cert.pem -noout -fingerprint
432 .SS Delivery Control Options
434 .B \-S <hosts> | \-\-smtphost <hosts>
435 (Keyword: smtp[host])
436 Specify a hunt list of hosts to forward mail to (one or more
437 hostnames, comma-separated). Hosts are tried in list order; the first
438 one that is up becomes the forwarding target for the current run. If
439 this option is not specified, 'localhost' is used as the default.
440 Each hostname may have a port number following the host name. The
441 port number is separated from the host name by a slash; the default
442 port is "smtp". If you specify an absolute path name (beginning with
443 a /), it will be interpreted as the name of a UNIX socket accepting
444 LMTP connections (such as is supported by the Cyrus IMAP daemon)
448 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
451 This option can be used with ODMR, and will make fetchmail a relay
452 between the ODMR server and SMTP or LMTP receiver.
454 .B \-\-fetchdomains <hosts>
455 (Keyword: fetchdomains)
456 In ETRN or ODMR mode, this option specifies the list of domains the
457 server should ship mail for once the connection is turned around. The
458 default is the FQDN of the machine running
461 .B \-D <domain> | \-\-smtpaddress <domain>
462 (Keyword: smtpaddress) Specify the domain to be appended to addresses
463 in RCPT TO lines shipped to SMTP. When this is not specified, the name
464 of the SMTP server (as specified by --smtphost) is used for SMTP/LMTP
465 and 'localhost' is used for UNIX socket/BSMTP.
467 .B \-\-smtpname <user@domain>
469 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
470 The default user is the current local user.
472 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
474 Specifies the list of numeric SMTP errors that are to be interpreted
475 as a spam-block response from the listener. A value of -1 disables
476 this option. For the command-line option, the list values should
479 .B \-m <command> | \-\-mda <command>
480 (Keyword: mda) You can force mail to be passed to an MDA directly
481 (rather than forwarded to port 25) with the --mda or -m option. To
482 avoid losing mail, use this option only with MDAs like maildrop, procmail or
483 sendmail that return a nonzero status on disk-full and other
484 resource-exhaustion errors; the nonzero status tells fetchmail that
485 delivery failed and prevents the message from being deleted off the
486 server. If \fIfetchmail\fR is running as root, it sets its user id to
487 that of the target user while delivering mail through an MDA. Some
488 possible MDAs are "/usr/sbin/sendmail -i -f %F %T", "/usr/bin/deliver"
489 and "/usr/bin/procmail -d %T" (but the latter is usually redundant as
490 it's what SMTP listeners normally forward to). Local delivery
491 addresses will be inserted into the MDA command wherever you place a
492 %T; the mail message's From address will be inserted where you place
493 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
494 both %T and %F, fetchmail encloses the addresses in single quotes ('),
495 after removing any single quotes they may contain, before the MDA
496 command is passed to the shell. Do \fINOT\fR use an MDA invocation
497 like "sendmail -i -t" that dispatches on the contents of To/Cc/Bcc, it
498 will create mail loops and bring the just wrath of many postmasters
499 down upon your head. Also, do \fInot\fR try to combine multidrop
500 mode with an MDA such as procmail that can only accept one address;
505 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
506 host and port \fBmust\fR be explicitly specified on each host in the
507 smtphost hunt list (see above) if this option is selected; the default
508 port 25 will (in accordance with RFC 2033) not be accepted.
510 .B \-\-bsmtp <filename>
512 Append fetched mail to a BSMTP file. This simply contains the SMTP
513 commands that would normally be generated by fetchmail when passing
514 mail to an SMTP listener daemon. An argument of '-' causes the mail
515 to be written to standard output. Note that fetchmail's
516 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
517 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
518 MAILBOXES below apply.
519 .SS Resource Limit Control Options
521 .B \-l <maxbytes> | \-\-limit <maxbytes>
522 (Keyword: limit) Takes a maximum octet size argument. Messages larger
523 than this size will not be fetched and will be left on the server (in
524 foreground sessions, the progress messages will note that they are
525 "oversized"). If the fetch protocol permits (in particular, under
526 IMAP or POP3 without the fetchall option) the message will not be
529 An explicit --limit of 0 overrides any limits set in your
530 run control file. This option is intended for those needing to
531 strictly control fetch time due to expensive and variable phone rates.
533 Combined with --limitflush, it can be used to delete oversized
534 messages waiting on a server. In daemon mode, oversize notifications
535 are mailed to the calling user (see the --warnings option). This
536 option does not work with ETRN or ODMR.
538 .B \-w <interval> | \-\-warnings <interval>
540 Takes an interval in seconds. When you call
542 with a 'limit' option in daemon mode, this controls the interval at
543 which warnings about oversized messages are mailed to the calling user
544 (or the user specified by the 'postmaster' option). One such
545 notification is always mailed at the end of the the first poll that
546 the oversized message is detected. Thereafter, renotification is
547 suppressed until after the warning interval elapses (it will take
548 place at the end of the first following poll).
550 .B \-b <count> | \-\-batchlimit <count>
551 (Keyword: batchlimit)
552 Specify the maximum number of messages that will be shipped to an SMTP
553 listener before the connection is deliberately torn down and rebuilt
554 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
555 overrides any limits set in your run control file. While
556 \fBsendmail\fR(8) normally initiates delivery of a message immediately
557 after receiving the message terminator, some SMTP listeners are not so
558 prompt. MTAs like \fIsmail\fR(8) may wait till the
559 delivery socket is shut down to deliver. This may produce annoying
560 delays when \fIfetchmail\fR is processing very large batches. Setting
561 the batch limit to some nonzero size will prevent these delays. This
562 option does not work with ETRN or ODMR.
564 .B \-B <number> | \-\-fetchlimit <number>
565 (Keyword: fetchlimit)
566 Limit the number of messages accepted from a given server in a single
567 poll. By default there is no limit. An explicit --fetchlimit of 0
568 overrides any limits set in your run control file.
569 This option does not work with ETRN or ODMR.
571 .B \-\-fetchsizelimit <number>
572 (Keyword: fetchsizelimit)
573 Limit the number of sizes of messages accepted from a given server in
574 a single transaction. This option is useful in reducing the delay in
575 downloading the first mail when there are too many mails in the
576 mailbox. By default, the limit is 100. If set to 0, sizes of all
577 messages are downloaded at the start.
578 This option does not work with ETRN or ODMR. For POP3, the only valid
581 .B \-\-fastuidl <number>
583 Do a binary instead of linear search for the first unseen UID. Binary
584 search avoids downloading the UIDs of all mails. This saves time
585 (especially in daemon mode) where downloading the same set of UIDs in
586 each poll is a waste of bandwidth. The number 'n' indicates how rarely
587 a linear search should be done. In daemon mode, linear search is used
588 once followed by binary searches in 'n-1' polls if 'n' is greater than
589 1; binary search is always used if 'n' is 1; linear search is always
590 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
591 1; otherwise linear search is used.
592 This option works with POP3 only.
594 .B \-e <count> | \-\-expunge <count>
596 Arrange for deletions to be made final after a given number of
597 messages. Under POP2 or POP3, fetchmail cannot make deletions final
598 without sending QUIT and ending the session -- with this option on,
599 fetchmail will break a long mail retrieval session into multiple
600 sub-sessions, sending QUIT after each sub-session. This is a good
601 defense against line drops on POP3 servers that do not do the
602 equivalent of a QUIT on hangup. Under IMAP,
604 normally issues an EXPUNGE command after each deletion in order to
605 force the deletion to be done immediately. This is safest when your
606 connection to the server is flaky and expensive, as it avoids
607 resending duplicate mail after a line hit. However, on large
608 mailboxes the overhead of re-indexing after every message can slam the
609 server pretty hard, so if your connection is reliable it is good to do
610 expunges less frequently. Also note that some servers enforce a delay
611 of a few seconds after each quit, so fetchmail may not be able to get
612 back in immediately after an expunge -- you may see "lock busy" errors
613 if this happens. If you specify this option to an integer N,
616 to only issue expunges on every Nth delete. An argument of zero
617 suppresses expunges entirely (so no expunges at all will be done until
618 the end of run). This option does not work with ETRN or ODMR.
619 .SS Authentication Options
621 .B \-u <name> | \-\-user <name> | \-\-username <name>
622 (Keyword: user[name])
623 Specifies the user identification to be used when logging in to the mailserver.
624 The appropriate user identification is both server and user-dependent.
625 The default is your login name on the client machine that is running
627 See USER AUTHENTICATION below for a complete description.
629 .B \-I <specification> | \-\-interface <specification>
631 Require that a specific interface device be up and have a specific local
632 or remote IPv4 (IPv6 is not supported by this option yet) address (or
633 range) before polling. Frequently \fIfetchmail\fP
634 is used over a transient point-to-point TCP/IP link established directly
635 to a mailserver via SLIP or PPP. That is a relatively secure channel.
636 But when other TCP/IP routes to the mailserver exist (e.g. when the link
637 is connected to an alternate ISP), your username and password may be
638 vulnerable to snooping (especially when daemon mode automatically polls
639 for mail, shipping a clear password over the net at predictable
640 intervals). The --interface option may be used to prevent this. When
641 the specified link is not up or is not connected to a matching IP
642 address, polling will be skipped. The format is:
645 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
648 The field before the first slash is the interface name (i.e. sl0, ppp0
649 etc.). The field before the second slash is the acceptable IP address.
650 The field after the second slash is a mask which specifies a range of
651 IP addresses to accept. If no mask is present 255.255.255.255 is
652 assumed (i.e. an exact match). This option is currently only supported
653 under Linux and FreeBSD. Please see the
655 section for below for FreeBSD specific information.
657 Note that this option may be removed from a future fetchmail version.
659 .B \-M <interface> | \-\-monitor <interface>
661 Daemon mode can cause transient links which are automatically taken down
662 after a period of inactivity (e.g. PPP links) to remain up
663 indefinitely. This option identifies a system TCP/IP interface to be
664 monitored for activity. After each poll interval, if the link is up but
665 no other activity has occurred on the link, then the poll will be
666 skipped. However, when fetchmail is woken up by a signal, the
667 monitor check is skipped and the poll goes through unconditionally.
668 This option is currently only supported under Linux and FreeBSD.
673 options to work for non root users under FreeBSD, the fetchmail binary
674 must be installed SGID kmem. This would be a security hole, but
675 fetchmail runs with the effective GID set to that of the kmem group
677 when interface data is being collected.
679 Note that this option may be removed from a future fetchmail version.
682 (Keyword: auth[enticate])
683 This option permits you to specify an authentication type (see USER
684 AUTHENTICATION below for details). The possible values are \fBany\fR,
685 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
686 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
687 \fBcram-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
688 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
689 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
690 KERBEROS\ 5); then it looks for methods that mask your password
691 (CRAM-MD5, X-OTP - note that NTLM and MSN are not autoprobed for POP3
692 and MSN is only supported for POP3); and only if the server doesn't
693 support any of those will it ship your password en clair. Other values
694 may be used to force various authentication methods
695 (\fBssh\fR suppresses authentication and is thus good for IMAP PREAUTH).
696 Any value other than \fBpassword\fR, \fBcram-md5\fR, \fBntlm\fR,
697 \&\fBmsn\fR or \fBotp\fR suppresses fetchmail's normal inquiry for a
698 password. Specify \fBssh\fR when you are using an end-to-end secure
699 connection such as an ssh tunnel; specify \fBgssapi\fR or
700 \&\fBkerberos_v4\fR if you are using a protocol variant that employs
701 GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
702 authentication. This option does not work with ETRN.
703 .SS Miscellaneous Options
705 .B \-f <pathname> | \-\-fetchmailrc <pathname>
706 Specify a non-default name for the
708 run control file. The pathname argument must be either "-" (a single
709 dash, meaning to read the configuration from standard input) or a
710 filename. Unless the --version option is also on, a named file
711 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
714 .B \-i <pathname> | \-\-idfile <pathname>
716 Specify an alternate name for the .fetchids file used to save POP3
719 .B \-n | \-\-norewrite
720 (Keyword: no rewrite)
723 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
724 fetched mail so that any mail IDs local to the server are expanded to
725 full addresses (@ and the mailserver hostname are appended). This enables
726 replies on the client to get addressed correctly (otherwise your
727 mailer might think they should be addressed to local users on the
728 client machine!). This option disables the rewrite. (This option is
729 provided to pacify people who are paranoid about having an MTA edit
730 mail headers and want to know they can prevent it, but it is generally
731 not a good idea to actually turn off rewrite.)
732 When using ETRN or ODMR, the rewrite option is ineffective.
734 .B \-E <line> | \-\-envelope <line>
735 (Keyword: envelope; Multidrop only)
737 In the configuration file, an enhanced syntax is used:
739 .B envelope [<count>] <line>
741 This option changes the header
743 assumes will carry a copy of the mail's envelope address. Normally
744 this is 'X-Envelope-To' but as this header is not standard, practice
745 varies. See the discussion of multidrop address handling below. As a
746 special case, 'envelope "Received"' enables parsing of sendmail-style
747 Received lines. This is the default, and it should not be necessary
748 unless you have globally disabled Received parsing with 'no envelope'
749 in the \fI.fetchmailrc\fR file.
751 The optional count argument (only available in the configuration file)
752 determines how many header lines of this kind are skipped. A count of 1
753 means: skip the first, take the second. A count of 2 means: skip the
754 first and second, take the third, and so on.
756 .B \-Q <prefix> | \-\-qvirtual <prefix>
757 (Keyword: qvirtual; Multidrop only)
758 The string prefix assigned to this option will be removed from the user
759 name found in the header specified with the \fIenvelope\fR option
760 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
761 if either is applicable). This option is useful if you are using
763 to collect the mail for an entire domain and your ISP (or your mail
764 redirection provider) is using qmail.
765 One of the basic features of qmail is the
769 message header. Whenever qmail delivers a message to a local mailbox
770 it puts the username and hostname of the envelope recipient on this
771 line. The major reason for this is to prevent mail loops. To set up
772 qmail to batch mail for a disconnected site the ISP-mailhost will have
773 normally put that site in its 'Virtualhosts' control file so it will
774 add a prefix to all mail addresses for this site. This results in mail
775 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
776 sent to 'username\&@\&userhost.userdom.dom.com' having a
777 \&'Delivered-To:' line of the form:
779 Delivered-To: mbox-userstr-username\&@\&userhost.userdom.dom.com
781 The ISP can make the 'mbox-userstr-' prefix anything they choose
782 but a string matching the user host name is likely.
783 By using the option 'envelope Delivered-To:' you can make fetchmail reliably
784 identify the original envelope recipient, but you have to strip the
785 \&'mbox-userstr-' prefix to deliver to the correct user.
786 This is what this option is for.
791 file, interpret any command-line options specified, and dump a
792 configuration report to standard output. The configuration report is
793 a data structure assignment in the language Python. This option
794 is meant to be used with an interactive
802 Removed before version 6.3.0, the required underlying inet6_apps library
803 had been discontinued and is no longer available.
805 .SH USER AUTHENTICATION AND ENCRYPTION
806 All modes except ETRN require authentication of the client to the server.
807 Normal user authentication in
809 is very much like the authentication mechanism of
811 The correct user-id and password depend upon the underlying security
812 system at the mailserver.
814 If the mailserver is a Unix machine on which you have an ordinary user
815 account, your regular login name and password are used with
817 If you use the same login name on both the server and the client machines,
818 you needn't worry about specifying a user-id with the
820 option \-\- the default behavior is to use your login name on the
821 client machine as the user-id on the server machine. If you use a
822 different login name on the server machine, specify that login name
825 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
830 fetchmail -u jsmith mailgrunt
832 The default behavior of
834 is to prompt you for your mailserver password before the connection is
835 established. This is the safest way to use
837 and ensures that your password will not be compromised. You may also specify
838 your password in your
840 file. This is convenient when using
842 in daemon mode or with scripts.
843 .SS Using netrc files
845 If you do not specify a password, and
847 cannot extract one from your
849 file, it will look for a
851 file in your home directory before requesting one interactively; if an
852 entry matching the mailserver is found in that file, the password will
853 be used. Fetchmail first looks for a match on poll name; if it finds none,
854 it checks for a match on via name. See the
856 man page for details of the syntax of the
858 file. To show a practical example, a .netrc might look like
862 machine hermes.example.org
867 You can repeat this block with different user information if you need to
868 provide more than one password.
870 This feature may allow you to avoid duplicating password
871 information in more than one file.
873 On mailservers that do not provide ordinary user accounts, your user-id and
874 password are usually assigned by the server administrator when you apply for
875 a mailbox on the server. Contact your server administrator if you don't know
876 the correct user-id and password for your mailbox account.
879 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
880 independent authentication using the
882 file on the mailserver side. Under this RPOP variant, a fixed
883 per-user ID equivalent to a password was sent in clear over a link to
884 a reserved port, with the command RPOP rather than PASS to alert the
885 server that it should do special checking. RPOP is supported
888 (you can specify 'protocol RPOP' to have the program send 'RPOP'
889 rather than 'PASS') but its use is strongly discouraged. This
890 facility was vulnerable to spoofing and was withdrawn in RFC1460.
892 RFC1460 introduced APOP authentication. In this variant of POP3,
893 you register an APOP password on your server host (the program
894 to do this with on the server is probably called \fIpopauth\fR(8)). You
895 put the same password in your
899 logs in, it sends a cryptographically secure hash of your password and
900 the server greeting time to the server, which can verify it by
901 checking its authorization database.
902 .SS Alternate authentication forms
904 If your \fIfetchmail\fR was built with Kerberos support and you specify
905 Kerberos authentication (either with --auth or the \fI.fetchmailrc\fR
906 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
907 ticket from the mailserver at the start of each query. Note: if
908 either the pollname or via name is 'hesiod', fetchmail will try to use
909 Hesiod to look up the mailserver.
911 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
912 expect the server to have RFC1731- or RFC1734-conformant GSSAPI
913 capability, and will use it. Currently this has only been tested over
914 Kerberos V, so you're expected to already have a ticket-granting
915 ticket. You may pass a username different from your principal name
916 using the standard \fB--user\fR command or by the \fI.fetchmailrc\fR
919 If your IMAP daemon returns the PREAUTH response in its greeting line,
920 fetchmail will notice this and skip the normal authentication step.
921 This can be useful, e.g. if you start imapd explicitly using ssh.
922 In this case you can declare the authentication value 'ssh' on that
923 site entry to stop \fI.fetchmail\fR from asking you for a password
926 If you are using POP3, and the server issues a one-time-password
927 challenge conforming to RFC1938, \fIfetchmail\fR will use your
928 password as a pass phrase to generate the required response. This
929 avoids sending secrets over the net unencrypted.
931 Compuserve's RPA authentication (similar to APOP) is supported. If you
932 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
933 authentication instead of sending over the password en clair if it
934 detects "@compuserve.com" in the hostname.
936 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
937 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
938 will try to perform an NTLM authentication (instead of sending over the
939 password en clair) whenever the server returns AUTH=NTLM in its
940 capability response. Specify a user option value that looks like
941 \&'user@domain': the part to the left of the @ will be passed as the
942 username and the part to the right as the NTLM domain.
943 .SS Secure Socket Layers (SSL)
945 You can access SSL encrypted services by specifying the --ssl option.
946 You can also do this using the "ssl" server option in the .fetchmailrc
947 file. With SSL encryption enabled, queries are initiated over a connection
948 after negotiating an SSL session. Some services, such as POP3 and IMAP,
949 have different well known ports defined for the SSL encrypted services.
950 The encrypted ports will be selected automatically when SSL is enabled and
951 no explicit port is specified.
953 When connecting to an SSL encrypted server, the server presents a certificate
954 to the client for validation. The certificate is checked to verify that
955 the common name in the certificate matches the name of the server being
956 contacted and that the effective and expiration dates in the certificate
957 indicate that it is currently valid. If any of these checks fail, a warning
958 message is printed, but the connection continues. The server certificate
959 does not need to be signed by any specific Certifying Authority and may
960 be a "self-signed" certificate.
962 Some SSL encrypted servers may request a client side certificate. A client
963 side public SSL certificate and private SSL key may be specified. If
964 requested by the server, the client certificate is sent to the server for
965 validation. Some servers may require a valid client certificate and may
966 refuse connections if a certificate is not provided or if the certificate
967 is not valid. Some servers may require client side certificates be signed
968 by a recognized Certifying Authority. The format for the key files and
969 the certificate files is that required by the underlying SSL libraries
970 (OpenSSL in the general case).
972 A word of care about the use of SSL: While above mentioned
973 setup with self-signed server certificates retrieved over the wires
974 can protect you from a passive eavesdropper it doesn't help against an
975 active attacker. It's clearly an improvement over sending the
976 passwords in clear but you should be aware that a man-in-the-middle
977 attack is trivially possible (in particular with tools such as dsniff,
978 http://www.monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
979 below for some examples) is preferable if you care seriously about the
980 security of your mailbox.
984 also supports authentication to the ESMTP server on the client side
985 according to RFC 2554. You can specify a name/password pair to be
986 used with the keywords 'esmtpname' and 'esmtppassword'; the former
987 defaults to the username of the calling user.
991 .B \-\-daemon <interval>
996 in daemon mode. You must specify a numeric argument which is a
997 polling interval in seconds.
1001 puts itself in background and runs forever, querying each specified
1002 host and then sleeping for the given polling interval.
1008 will, therefore, poll all the hosts described in your
1010 file (except those explicitly excluded with the 'skip' verb) once
1011 every fifteen minutes.
1013 It is possible to set a polling interval
1016 file by saying 'set daemon <interval>', where <interval> is an
1017 integer number of seconds. If you do this, fetchmail will always
1018 start in daemon mode unless you override it with the command-line
1019 option --daemon 0 or -d0.
1021 Only one daemon process is permitted per user; in daemon mode,
1023 makes a per-user lockfile to guarantee this.
1025 Normally, calling fetchmail with a daemon in the background sends a
1026 wake-up signal to the daemon, forcing it to poll mailservers
1027 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1028 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1029 flags indicating that connections have wedged due to failed
1030 authentication or multiple timeouts.
1034 will kill a running daemon process instead of waking it up (if there
1035 is no such process, \fIfetchmail\fP will notify you.
1036 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1037 will kill the running daemon process and then quit. Otherwise,
1038 \fIfetchmail\fP will first kill a running daemon process and then
1039 continue running with the other options.
1044 .B \-\-logfile <filename>
1045 option (keyword: set logfile) is only effective when fetchmail is
1046 detached. This option allows you to redirect status messages
1047 into a specified logfile (follow the option with the logfile name). The
1048 logfile is opened for append, so previous messages aren't deleted. This
1049 is primarily useful for debugging configurations.
1053 option (keyword: set syslog) allows you to redirect status and error
1054 messages emitted to the
1056 system daemon if available.
1057 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1058 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1059 This option is intended for logging status and error messages which
1060 indicate the status of the daemon and the results while fetching mail
1062 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1063 file are still written to stderr, or to the specified log file.
1066 option turns off use of
1068 assuming it's turned on in the
1073 .B \-\-logfile <file>
1080 option suppresses backgrounding and detachment of the
1081 daemon process from its control terminal. This is useful
1082 for debugging or when fetchmail runs as the child of a supervisor
1087 Note that this also causes the logfile option to be
1088 ignored (though perhaps it shouldn't).
1090 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1091 transient errors (such as DNS failures or sendmail delivery refusals)
1092 may force the fetchall option on for the duration of the next polling
1093 cycle. This is a robustness feature. It means that if a message is
1094 fetched (and thus marked seen by the mailserver) but not delivered
1095 locally due to some transient error, it will be re-fetched during the
1096 next poll cycle. (The IMAP logic doesn't delete messages until
1097 they're delivered, so this problem does not arise.)
1099 If you touch or change the
1101 file while fetchmail is running in daemon mode, this will be detected
1102 at the beginning of the next poll cycle. When a changed
1104 is detected, fetchmail rereads it and restarts from scratch (using
1105 exec(2); no state information is retained in the new instance). Note also
1106 that if you break the
1108 file's syntax, the new instance will softly and silently vanish away
1111 .SH ADMINISTRATIVE OPTIONS
1114 .B \-\-postmaster <name>
1115 option (keyword: set postmaster) specifies the last-resort username to
1116 which multidrop mail is to be forwarded if no matching local recipient
1117 can be found. It is also used as destination of undeliverable mail if
1118 the 'bouncemail' global option is off and additionally for spam-blocked
1119 mail if the 'bouncemail' global option is off and the 'spambounce'
1120 global option is on. This option defaults to the user who invoked
1122 If the invoking user is root, then the default of this option is
1123 the user 'postmaster'. Setting postmaster to the empty string causes
1124 such mail as described above to be discarded - this however is usually a
1126 See also the description of the 'FETCHMAILUSER' environment variable in
1127 the ENVIRONMENT section below.
1131 behaves like the "set no bouncemail" global option, which see.
1135 option (keyword: set invisible) tries to make fetchmail invisible.
1136 Normally, fetchmail behaves like any other MTA would -- it generates a
1137 Received header into each message describing its place in the chain of
1138 transmission, and tells the MTA it forwards to that the mail came from
1139 the machine fetchmail itself is running on. If the invisible option
1140 is on, the Received header is suppressed and fetchmail tries to spoof
1141 the MTA it forwards to into thinking it came directly from the
1146 option (keyword: set showdots) forces fetchmail to show progress dots
1147 even if the current tty is not stdout (for example logfiles).
1148 Starting with fetchmail version 5.3.0,
1149 progress dots are only shown on stdout by default.
1153 option, you can ask fetchmail to add information to the Received
1154 header on the form "polling {label} account {user}", where {label} is
1155 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1156 and {user} is the username which is used to log on to the mail
1157 server. This header can be used to make filtering email where no
1158 useful header information is available and you want mail from
1159 different accounts sorted into different mailboxes (this could, for
1160 example, occur if you have an account on the same server running a
1161 mailing list, and are subscribed to the list using that account). The
1162 default is not adding any such header. In
1164 this is called 'tracepolls'.
1166 .SH RETRIEVAL FAILURE MODES
1167 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1168 bulletproof. In normal operation forwarding to port 25, no message is
1169 ever deleted (or even marked for deletion) on the host until the SMTP
1170 listener on the client side has acknowledged to \fIfetchmail\fR that
1171 the message has been either accepted for delivery or rejected due to a
1174 When forwarding to an MDA, however, there is more possibility
1175 of error. Some MDAs are 'safe' and reliably return a nonzero status
1176 on any delivery error, even one due to temporary resource limits.
1179 program is like this; so are most programs designed as mail transport
1184 These programs give back a reliable positive acknowledgement and
1185 can be used with the mda option with no risk of mail loss. Unsafe
1186 MDAs, though, may return 0 even on delivery failure. If this
1187 happens, you will lose mail.
1189 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1190 messages, leaving untouched (and undeleted) messages you have already
1191 read directly on the server (or fetched with a previous \fIfetchmail
1192 --keep\fR). But you may find that messages you've already read on the
1193 server are being fetched (and deleted) even when you don't specify
1194 --all. There are several reasons this can happen.
1196 One could be that you're using POP2. The POP2 protocol includes no
1197 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1198 must treat all messages as new all the time. But POP2 is obsolete, so
1201 A potential POP3 problem might be servers that insert messages
1202 in the middle of mailboxes (some VMS implementations of mail are
1203 rumored to do this). The \fIfetchmail\fR code assumes that new
1204 messages are appended to the end of the mailbox; when this is not true
1205 it may treat some old messages as new and vice versa. Using UIDL might
1206 fix this, otherwise, consider switching to IMAP.
1208 Yet another POP3 problem is that if they can't make tempfiles in the
1209 user's home directory, some POP3 servers will hand back an
1210 undocumented response that causes fetchmail to spuriously report "No
1213 The IMAP code uses the presence or absence of the server flag \eSeen
1214 to decide whether or not a message is new. This isn't the right thing
1215 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1216 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1217 the BSD-style Status flags set by mail user agents and set the \eSeen
1218 flag from them when appropriate. All Unix IMAP servers we know of do
1219 this, though it's not specified by the IMAP RFCs. If you ever trip over
1220 a server that doesn't, the symptom will be that messages you have
1221 already read on your host will look new to the server. In this
1222 (unlikely) case, only messages you fetched with \fIfetchmail --keep\fR
1223 will be both undeleted and marked old.
1225 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1226 instead, it asks the server's SMTP listener to start a queue flush
1227 to the client via SMTP. Therefore it sends only undelivered messages.
1230 Many SMTP listeners allow administrators to set up 'spam filters' that
1231 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1232 triggers this feature will elicit an SMTP response which
1233 (unfortunately) varies according to the listener.
1237 return an error code of 571.
1239 According to RFC2821, the correct thing to return in this situation is
1240 550 "Requested action not taken: mailbox unavailable" (the draft adds
1241 "[E.g., mailbox not found, no access, or command rejected for policy
1244 Older versions of the
1246 MTA return 501 "Syntax error in parameters or arguments".
1250 MTA runs 554 as an antispam response.
1253 may reject code with a 500 response (followed by an enhanced status
1254 code that contains more information).
1258 treats as antispam responses and discards
1259 the message can be set with the 'antispam' option. This is one of the
1261 three circumstance under which fetchmail ever discards mail (the others
1262 are the 552 and 553 errors described below, and the suppression of
1263 multidropped messages with a message-ID already seen).
1267 is fetching from an IMAP server, the antispam response will be detected and
1268 the message rejected immediately after the headers have been fetched,
1269 without reading the message body. Thus, you won't pay for downloading
1270 spam message bodies.
1272 By default, the list of antispam responses is empty.
1274 If the \fIspambounce\fR global option is on, mail that is spam-blocked
1275 triggers an RFC1892/RFC1894 bounce message informing the originator that
1276 we do not accept mail from it. See also BUGS.
1278 .SH SMTP/ESMTP ERROR HANDLING
1279 Besides the spam-blocking described above, fetchmail takes special
1280 actions on the following SMTP/ESMTP error responses
1282 452 (insufficient system storage)
1283 Leave the message in the server mailbox for later retrieval.
1285 552 (message exceeds fixed maximum message size)
1286 Delete the message from the server. Send bounce-mail to the
1289 553 (invalid sending domain)
1290 Delete the message from the server. Don't even try to send
1291 bounce-mail to the originator.
1293 Other errors trigger bounce mail back to the originator. See also BUGS.
1295 .SH THE RUN CONTROL FILE
1296 The preferred way to set up fetchmail is to write a
1297 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1298 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1299 When there is a conflict between the command-line arguments and the
1300 arguments in this file, the command-line arguments take precedence.
1302 To protect the security of your passwords,
1303 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1305 will complain and exit otherwise (this check is suppressed when
1308 You may read the \fI.fetchmailrc\fR file as a list of commands to
1311 is called with no arguments.
1312 .SS Run Control Syntax
1314 Comments begin with a '#' and extend through the end of the line.
1315 Otherwise the file consists of a series of server entries or global
1316 option statements in a free-format, token-oriented syntax.
1318 There are four kinds of tokens: grammar keywords, numbers
1319 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1320 A quoted string is bounded by double quotes and may contain
1321 whitespace (and quoted digits are treated as a string). Note that
1322 quoted strings will also contain line feed characters if they run across
1323 two or more lines - so be sure that your strings are not word-wrapped
1324 unless you want the embedded CR or LF characters.
1325 An unquoted string is any whitespace-delimited token that is neither
1326 numeric, string quoted nor contains the special characters ',', ';',
1329 Any amount of whitespace separates tokens in server entries, but is
1330 otherwise ignored. You may use escapes (\en for LF, \et for HT,
1331 \&\eb for BS, \er for CR, \e\fInnn\fP for decimal (where nnn cannot start
1332 with a 0), \e0\fIooo\fP for octal, and \ex\fIhh\fP for hex) to embed
1333 non-printable characters or string delimiters in strings.
1336 while these resemble C-style escape sequences, fetchmail only supports
1337 these seven styles. C supports more escape sequences that consist of
1338 backslash (\e) and a single character, but does not support decimal
1339 codes and does not require the leading 0 in octal notation. Example:
1340 fetchmail interprets \e233 the same as \exE9 (Latin small letter e
1341 with acute), where C would interpret \e233 as octal 0233 = \ex9B (CSI,
1342 control sequence introducer).
1344 Each server entry consists of one of the keywords 'poll' or 'skip',
1345 followed by a server name, followed by server options, followed by any
1346 number of user descriptions. Note: the most common cause of syntax
1347 errors is mixing up user and server options.
1349 For backward compatibility, the word 'server' is a synonym for 'poll'.
1351 You can use the noise keywords 'and', 'with',
1352 \&'has', 'wants', and 'options' anywhere in an entry to make
1353 it resemble English. They're ignored, but but can make entries much
1354 easier to read at a glance. The punctuation characters ':', ';' and
1355 \&',' are also ignored.
1358 The 'poll' verb tells fetchmail to query this host when it is run with
1359 no arguments. The 'skip' verb tells
1361 not to poll this host unless it is explicitly named on the command
1362 line. (The 'skip' verb allows you to experiment with test entries
1363 safely, or easily disable entries for hosts that are temporarily down.)
1365 .SS Keyword/Option Summary
1366 Here are the legal options. Keyword suffixes enclosed in
1367 square brackets are optional. Those corresponding to short command-line
1368 options are followed by '-' and the appropriate option letter. If
1369 option is only relevant to a single mode of operation, it is noted as
1370 's' or 'm' for singledrop- or multidrop-mode, respectively.
1372 Here are the legal global options:
1376 Keyword Opt Mode Function
1379 Set a background poll interval in seconds.
1381 set postmaster \& \& T{
1382 Give the name of the last-resort mail recipient (default: user running
1383 fetchmail, "postmaster" if run by the root user)
1385 set bouncemail \& \& T{
1386 Direct error mail to the sender (default)
1388 set no bouncemail \& \& T{
1389 Direct error mail to the local postmaster (as per the 'postmaster'
1390 global option above).
1392 set no spambounce \& \& T{
1393 Do not bounce spam-blocked mail (default).
1395 set spambounce \& \& T{
1396 Bounce blocked spam-blocked mail (as per the 'antispam' user option)
1397 back to the destination as indicated by the 'bouncemail' global option.
1398 Warning: Do not use this to bounce spam back to the sender - most spam
1399 is sent with false sender address and thus this option hurts innocent
1402 set logfile -L \& T{
1403 Name of a file to append error and status messages to.
1406 Name of the file to store UID lists in.
1409 Do error logging through syslog(3).
1411 set no syslog \& \& T{
1412 Turn off error logging through syslog(3). (default)
1414 set properties \& \& T{
1415 String value that is ignored by fetchmail (may be used by extension
1420 Here are the legal server options:
1424 Keyword Opt Mode Function
1427 Specify DNS name of mailserver, overriding poll name
1430 Specify protocol (case insensitive):
1431 POP2, POP3, IMAP, APOP, KPOP
1433 local[domains] \& m T{
1434 Specify domain(s) to be regarded as local
1437 Specify TCP/IP service port (obsolete, use 'service' instead).
1440 Specify service name (a numeric value is also allowed and
1441 considered a TCP/IP port number).
1443 auth[enticate] \& \& T{
1444 Set authentication type (default 'any')
1447 Server inactivity timeout in seconds (default 300)
1450 Specify envelope-address header name
1453 Disable looking for envelope address
1456 Qmail virtual domain prefix to remove from user name
1459 Specify alternate DNS names of mailserver
1462 specify IP interface(s) that must be up for server poll to take place
1465 Specify IP address to monitor for activity
1468 Specify command through which to make server connections.
1471 Specify command through which to make listener connections.
1474 Enable DNS lookup for multidrop (default)
1477 Disable DNS lookup for multidrop
1480 Do comparison by IP address for multidrop
1482 no checkalias \& m T{
1483 Do comparison by name for multidrop (default)
1486 Force POP3 to use client-side UIDLs (recommended)
1489 Turn off POP3 use of client-side UIDLs (default)
1492 Only check this site every N poll cycles; N is a numeric argument.
1495 Add poll tracing information to the Received header
1498 Set Kerberos principal (only useful with imap and kerberos)
1501 Set name for RFC2554 authentication to the ESMTP server.
1503 esmtppassword \& \& T{
1504 Set password for RFC2554 authentication to the ESMTP server.
1508 Here are the legal user options:
1512 Keyword Opt Mode Function
1515 Set remote user name
1516 (local user name if name followed by 'here')
1519 Connect local and remote user names
1522 Connect local and remote user names
1525 Specify remote account password
1528 Connect to server over the specified base protocol using SSL encryption
1531 Specify file for client side public SSL certificate
1534 Specify file for client side private SSL key
1537 Force ssl protocol for connection
1540 Specify remote folder to query
1543 Specify smtp host(s) to forward to
1545 fetchdomains \& m T{
1546 Specify domains for which mail should be fetched
1548 smtpaddress -D \& T{
1549 Specify the domain to be put in RCPT TO lines
1552 Specify the user and domain to be put in RCPT TO lines
1555 Specify what SMTP returns are interpreted as spam-policy blocks
1558 Specify MDA for local delivery
1561 Specify BSMTP batch file to append to
1564 Command to be executed before each connection
1566 postconnect \& \& T{
1567 Command to be executed after each connection
1570 Don't delete seen messages from server
1573 Flush all seen messages before querying (DANGEROUS)
1576 Flush all oversized messages before querying
1579 Fetch all messages whether seen or not
1582 Rewrite destination addresses for reply (default)
1585 Strip carriage returns from ends of lines
1588 Force carriage returns at ends of lines
1591 Force BODY=8BITMIME to ESMTP listener
1594 Strip Status and X-Mozilla-Status lines out of incoming mail
1596 dropdelivered \& \& T{
1597 Strip Delivered-To lines out of incoming mail
1600 Convert quoted-printable to 8-bit in MIME messages
1603 Idle waiting for new messages after each poll (IMAP only)
1606 Delete seen messages from server (default)
1609 Don't flush all seen messages before querying (default)
1611 no fetchall \& \& T{
1612 Retrieve only new messages (default)
1615 Don't rewrite headers
1618 Don't strip carriage returns (default)
1621 Don't force carriage returns at EOL (default)
1623 no pass8bits \& \& T{
1624 Don't force BODY=8BITMIME to ESMTP listener (default)
1626 no dropstatus \& \& T{
1627 Don't drop Status headers (default)
1629 no dropdelivered \& \& T{
1630 Don't drop Delivered-To headers (default)
1632 no mimedecode \& \& T{
1633 Don't convert quoted-printable to 8-bit in MIME messages (default)
1636 Don't idle waiting for new messages after each poll (IMAP only)
1639 Set message size limit
1642 Set message size warning interval
1645 Max # messages to forward in single connect
1648 Max # messages to fetch in single connect
1650 fetchsizelimit \& \& T{
1651 Max # message sizes to fetch in single transaction
1654 Use binary search for first unseen message (POP3 only)
1657 Perform an expunge on every #th message (IMAP and POP3 only)
1660 String value is ignored by fetchmail (may be used by extension scripts)
1664 Remember that all user options must \fIfollow\fR all server options.
1666 In the .fetchmailrc file, the 'envelope' string argument may be
1667 preceded by a whitespace-separated number. This number, if specified,
1668 is the number of such headers to skip over (that is, an argument of 1
1669 selects the second header of the given type). This is sometime useful
1670 for ignoring bogus envelope headers created by an ISP's local delivery
1671 agent or internal forwards (through mail inspection systems, for
1673 .SS Keywords Not Corresponding To Option Switches
1675 The 'folder' and 'smtphost' options (unlike their command-line
1676 equivalents) can take a space- or comma-separated list of names
1679 All options correspond to the obvious command-line arguments, except
1680 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1681 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1682 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1683 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1684 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'idle/no
1685 idle', and 'no envelope'.
1687 The 'via' option is for if you want to have more
1688 than one configuration pointing at the same site. If it is present,
1689 the string argument will be taken as the actual DNS name of the
1690 mailserver host to query.
1691 This will override the argument of poll, which can then simply be a
1692 distinct label for the configuration (e.g. what you would give on the
1693 command line to explicitly query this host).
1695 The 'interval' option (which takes a numeric argument) allows you to poll a
1696 server less frequently than the basic poll interval. If you say
1697 \&'interval N' the server this option is attached to will only be
1698 queried every N poll intervals.
1700 The 'is' or 'to' keywords associate the following local (client)
1701 name(s) (or server-name to client-name mappings separated by =) with
1702 the mailserver user name in the entry. If an is/to list has '*' as
1703 its last name, unrecognized names are simply passed through.
1705 A single local name can be used to support redirecting your mail when
1706 your username on the client machine is different from your name on the
1707 mailserver. When there is only a single local name, mail is forwarded
1708 to that local username regardless of the message's Received, To, Cc,
1709 and Bcc headers. In this case
1711 never does DNS lookups.
1713 When there is more than one local name (or name mapping) the
1714 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1715 headers of retrieved mail (this is 'multidrop mode'). It looks for
1716 addresses with hostname parts that match your poll name or your 'via',
1717 \&'aka' or 'localdomains' options, and usually also for hostname parts
1718 which DNS tells it are aliases of the mailserver. See the discussion
1719 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1720 matching addresses are handled.
1722 If \fIfetchmail\fR cannot match any mailserver usernames or
1723 localdomain addresses, the mail will be bounced.
1724 Normally it will be bounced to the sender, but if the 'bouncemail'
1725 global option is off, the mail will go to the local postmaster instead.
1726 (see the 'postmaster' global option). See also BUGS.
1728 The 'dns' option (normally on) controls the way addresses from
1729 multidrop mailboxes are checked. On, it enables logic to check each
1730 host address that doesn't match an 'aka' or 'localdomains' declaration
1731 by looking it up with DNS. When a mailserver username is recognized
1732 attached to a matching hostname part, its local mapping is added to
1733 the list of local recipients.
1735 The 'checkalias' option (normally off) extends the lookups performed
1736 by the 'dns' keyword in multidrop mode, providing a way to cope with
1737 remote MTAs that identify themselves using their canonical name, while
1738 they're polled using an alias.
1739 When such a server is polled, checks to extract the envelope address
1742 reverts to delivery using the To/Cc/Bcc headers (See below
1743 \&'Header vs. Envelope addresses').
1744 Specifying this option instructs
1746 to retrieve all the IP addresses associated with both the poll name
1747 and the name used by the remote MTA and to do a comparison of the IP
1748 addresses. This comes in handy in situations where the remote server
1749 undergoes frequent canonical name changes, that would otherwise
1750 require modifications to the rcfile. 'checkalias' has no effect if
1751 \&'no dns' is specified in the rcfile.
1753 The 'aka' option is for use with multidrop mailboxes. It allows you
1754 to pre-declare a list of DNS aliases for a server. This is an
1755 optimization hack that allows you to trade space for speed. When
1757 while processing a multidrop mailbox, grovels through message headers
1758 looking for names of the mailserver, pre-declaring common ones can
1759 save it from having to do DNS lookups. Note: the names you give
1760 as arguments to 'aka' are matched as suffixes -- if you specify
1761 (say) 'aka netaxs.com', this will match not just a hostname
1762 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1763 (say) pop3.netaxs.com and mail.netaxs.com.
1765 The 'localdomains' option allows you to declare a list of domains
1766 which fetchmail should consider local. When fetchmail is parsing
1767 address lines in multidrop modes, and a trailing segment of a host
1768 name matches a declared local domain, that address is passed through
1769 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1772 If you are using 'localdomains', you may also need to specify \&'no
1773 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1774 an envelope address from the Received line or X-Envelope-To header or
1775 whatever header has been previously set by 'envelope'. If you set 'no
1776 envelope' in the defaults entry it is possible to undo that in
1777 individual entries by using 'envelope <string>'. As a special case,
1778 \&'envelope "Received"' restores the default parsing of
1781 The \fBpassword\fR option requires a string argument, which is the password
1782 to be used with the entry's server.
1784 The 'preconnect' keyword allows you to specify a shell command to be
1785 executed just before each time
1787 establishes a mailserver connection. This may be useful if you are
1788 attempting to set up secure POP connections with the aid of
1790 If the command returns a nonzero status, the poll of that mailserver
1793 Similarly, the 'postconnect' keyword similarly allows you to specify a
1794 shell command to be executed just after each time a mailserver
1795 connection is taken down.
1797 The 'forcecr' option controls whether lines terminated by LF only are
1798 given CRLF termination before forwarding. Strictly speaking RFC821
1799 requires this, but few MTAs enforce the requirement it so this option
1800 is normally off (only one such MTA, qmail, is in significant use at
1803 The 'stripcr' option controls whether carriage returns are stripped
1804 out of retrieved mail before it is forwarded. It is normally not
1805 necessary to set this, because it defaults to 'on' (CR stripping
1806 enabled) when there is an MDA declared but 'off' (CR stripping
1807 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1808 both on, 'stripcr' will override.
1810 The 'pass8bits' option exists to cope with Microsoft mail programs that
1811 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1812 this option off (the default) and such a header present,
1814 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1815 messages actually using 8-bit ISO or KOI-8 character sets, which will
1816 be garbled by having the high bits of all characters stripped. If
1817 \&'pass8bits' is on,
1819 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1820 the listener is 8-bit-clean (as all the major ones now are) the right
1821 thing will probably result.
1823 The 'dropstatus' option controls whether nonempty Status and
1824 X-Mozilla-Status lines are retained in fetched mail (the default) or
1825 discarded. Retaining them allows your MUA to see what messages (if
1826 any) were marked seen on the server. On the other hand, it can
1827 confuse some new-mail notifiers, which assume that anything with a
1828 Status line in it has been seen. (Note: the empty Status lines
1829 inserted by some buggy POP servers are unconditionally discarded.)
1831 The 'dropdelivered' option controls whether Delivered-To headers will
1832 be kept in fetched mail (the default) or discarded. These headers are
1833 added by Qmail and Postfix mailservers in order to avoid mail loops but
1834 may get in your way if you try to "mirror" a mailserver within the same
1835 domain. Use with caution.
1837 The 'mimedecode' option controls whether MIME messages using the
1838 quoted-printable encoding are automatically converted into pure 8-bit
1839 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1840 listener (that includes all of the major MTAs like sendmail), then
1841 this will automatically convert quoted-printable message headers and
1842 data into 8-bit data, making it easier to understand when reading
1843 mail. If your e-mail programs know how to deal with MIME messages,
1844 then this option is not needed. The mimedecode option is off by
1845 default, because doing RFC2047 conversion on headers throws away
1846 character-set information and can lead to bad results if the encoding
1847 of the headers differs from the body encoding.
1849 The 'idle' option is intended to be used with IMAP servers supporting
1850 the RFC2177 IDLE command extension, but does not strictly require it.
1851 If it is enabled, and fetchmail detects that IDLE is supported, an
1852 IDLE will be issued at the end of each poll. This will tell the IMAP
1853 server to hold the connection open and notify the client when new mail
1854 is available. If IDLE is not supported, fetchmail will simulate it by
1855 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1856 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1857 sequences. On the other hand, an IDLE connection will eat almost all
1858 of your fetchmail's time, because it will never drop the connection
1859 and allow other pools to occur unless the server times out the IDLE.
1860 It also doesn't work with multiple folders; only the first folder will
1864 The 'properties' option is an extension mechanism. It takes a string
1865 argument, which is ignored by fetchmail itself. The string argument may be
1866 used to store configuration information for scripts which require it.
1867 In particular, the output of '--configdump' option will make properties
1868 associated with a user entry readily available to a Python script.
1870 .SS Miscellaneous Run Control Options
1871 The words 'here' and 'there' have useful English-like
1872 significance. Normally 'user eric is esr' would mean that
1873 mail for the remote user 'eric' is to be delivered to 'esr',
1874 but you can make this clearer by saying 'user eric there is esr here',
1875 or reverse it by saying 'user esr here is eric there'
1877 Legal protocol identifiers for use with the 'protocol' keyword are:
1881 pop2 (or POP2) (legacy, to be removed from future release)
1890 Legal authentication types are 'any', 'password', 'kerberos',
1891 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn'
1892 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1893 authentication by normal transmission of a password (the password may be
1894 plain text or subject to protocol-specific encryption as in APOP);
1895 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1896 start of each query instead, and send an arbitrary string as the
1897 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1898 See the description of the 'auth' keyword for more.
1900 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1901 authentication. These defaults may be overridden by later options.
1903 There are some global option statements: 'set logfile'
1904 followed by a string sets the same global specified by --logfile. A
1905 command-line --logfile option will override this. Note that --logfile is
1906 only effective if fetchmail detaches itself from the terminal. Also,
1907 'set daemon' sets the poll interval as --daemon does. This can be
1908 overridden by a command-line --daemon option; in particular --daemon 0
1909 can be used to force foreground operation. The 'set postmaster'
1910 statement sets the address to which multidrop mail defaults if there are
1911 no local matches. Finally, 'set syslog' sends log messages to
1914 .SH INTERACTION WITH RFC 822
1915 When trying to determine the originating address of a message,
1916 fetchmail looks through headers in the following order:
1920 Resent-Sender: (ignored if it doesn't contain an @ or !)
1921 Sender: (ignored if it doesn't contain an @ or !)
1928 The originating address is used for logging, and to set the MAIL FROM
1929 address when forwarding to SMTP. This order is intended to cope
1930 gracefully with receiving mailing list messages in multidrop mode. The
1931 intent is that if a local address doesn't exist, the bounce message
1932 won't be returned blindly to the author or to the list itself, but
1933 rather to the list manager (which is less annoying).
1935 In multidrop mode, destination headers are processed as follows:
1936 First, fetchmail looks for the Received: header (or whichever one is
1937 specified by the 'envelope' option) to determine the local
1938 recipient address. If the mail is addressed to more than one recipient,
1939 the Received line won't contain any information regarding recipient addresses.
1941 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1942 lines. If they exist, they should contain the final recipients and
1943 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1944 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1945 looked for. (The presence of a Resent-To: is taken to imply that the
1946 person referred by the To: address has already received the original
1949 .SH CONFIGURATION EXAMPLES
1950 Note that although there are password declarations in a good many
1951 of the examples below, this is mainly for illustrative purposes.
1952 We recommend stashing account/password pairs in your $HOME/.netrc
1953 file, where they can be used not just by fetchmail but by ftp(1) and
1959 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1965 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
1968 Or, using some abbreviations:
1971 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
1974 Multiple servers may be listed:
1977 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
1978 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
1981 Here's a version of those two with more whitespace and some noise words:
1984 poll pop.provider.net proto pop3
1985 user "jsmith", with password secret1, is "jsmith" here;
1986 poll other.provider.net proto pop2:
1987 user "John.Smith", with password "My^Hat", is "John.Smith" here;
1990 This version is much easier to read and doesn't cost significantly
1991 more (parsing is done only once, at startup time).
1994 If you need to include whitespace in a parameter string, enclose the
1995 string in double quotes. Thus:
1998 poll mail.provider.net with proto pop3:
1999 user "jsmith" there has password "u can't krak this"
2000 is jws here and wants mda "/bin/mail"
2003 You may have an initial server description headed by the keyword
2004 \&'defaults' instead of 'poll' followed by a name. Such a record
2005 is interpreted as defaults for all queries to use. It may be overwritten
2006 by individual server descriptions. So, you could write:
2011 poll pop.provider.net
2013 poll mail.provider.net
2014 user "jjsmith" there has password "secret2"
2017 It's possible to specify more than one user per server (this is only
2018 likely to be useful when running fetchmail in daemon mode as root).
2019 The 'user' keyword leads off a user description, and every user specification
2020 in a multi-user entry must include it. Here's an example:
2023 poll pop.provider.net proto pop3 port 3111
2024 user "jsmith" with pass "secret1" is "smith" here
2025 user jones with pass "secret2" is "jjones" here keep
2028 This associates the local username 'smith' with the pop.provider.net
2029 username 'jsmith' and the local username 'jjones' with the
2030 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2031 server after download.
2033 Here's what a simple retrieval configuration for a multi-drop mailbox
2037 poll pop.provider.net:
2038 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2041 This says that the mailbox of account 'maildrop' on the server is a
2042 multi-drop box, and that messages in it should be parsed for the
2043 server user names 'golux', 'hurkle', and 'snark'. It further
2044 specifies that 'golux' and 'snark' have the same name on the
2045 client as on the server, but mail for server user 'hurkle' should be
2046 delivered to client user 'happy'.
2048 Here's an example of another kind of multidrop connection:
2051 poll pop.provider.net localdomains loonytoons.org toons.org:
2052 user maildrop with pass secret1 to * here
2055 This also says that the mailbox of account 'maildrop' on the server is
2056 a multi-drop box. It tells fetchmail that any address in the
2057 loonytoons.org or toons.org domains (including sub-domain addresses like
2058 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2059 listener without modification. Be careful of mail loops if you do this!
2061 Here's an example configuration using ssh and the plugin option. The
2062 queries are made directly on the stdin and stdout of imapd via ssh.
2063 Note that in this setup, IMAP authentication can be skipped.
2066 poll mailhost.net with proto imap:
2067 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2068 user esr is esr here
2071 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2072 Use the multiple-local-recipients feature with caution -- it can bite.
2073 All multidrop features are ineffective in ETRN and ODMR modes.
2075 Also, note that in multidrop mode duplicate mails are suppressed. A
2076 piece of mail is considered duplicate if it has the same message-ID as
2077 the message immediately preceding and more than one addressee. Such
2078 runs of messages may be generated when copies of a message addressed
2079 to multiple users are delivered to a multidrop box.
2081 .SS Header vs. Envelope addresses
2082 The fundamental problem is that by having your mailserver toss several
2083 peoples' mail in a single maildrop box, you may have thrown away
2084 potentially vital information about who each piece of mail was
2085 actually addressed to (the 'envelope address', as opposed to the
2086 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2087 at the receiving end). This 'envelope address' is the address you need
2088 in order to reroute mail properly.
2092 can deduce the envelope address. If the mailserver MTA is
2094 and the item of mail had just one recipient, the MTA will have written
2095 a 'by/for' clause that gives the envelope addressee into its Received
2096 header. But this doesn't work reliably for other MTAs, nor if there is
2097 more than one recipient. By default, \fIfetchmail\fR looks for
2098 envelope addresses in these lines; you can restore this default with
2099 -E "Received" or \&'envelope Received'.
2101 .B As a better alternative,
2102 some SMTP listeners and/or mail servers insert a header
2103 in each message containing a copy of the envelope addresses. This
2104 header (when it exists) is often 'X-Original-To', 'Delivered-To' or
2105 'X-Envelope-To'. Fetchmail's assumption about this can be changed with
2106 the -E or 'envelope' option. Note that writing an envelope header of
2107 this kind exposes the names of recipients (including blind-copy
2108 recipients) to all receivers of the messages, so the upstream must store
2109 one copy of the message per recipient to avoid becoming a privacy problem.
2111 Postfix, since version 2.0, writes an X-Original-To: header which
2112 contains a copy of the envelope as it was received.
2114 Qmail and Postfix generally write a 'Delivered-To' header upon
2115 delivering the message to the mail spool and use it to avoid mail loops.
2116 Qmail virtual domains however will prefix the user name with a string
2117 that normally matches the user's domain. To remove this prefix you can
2118 use the -Q or 'qvirtual' option.
2120 Sometimes, unfortunately, neither of these methods works. That is the
2121 point when you should contact your ISP and ask them to provide such an
2122 envelope header, and you should not use multidrop in this situation.
2123 When they all fail, fetchmail must fall back on the contents of To/Cc
2124 headers (Bcc headers are not available - see below) to try to determine
2125 recipient addressees -- and these are unreliable.
2126 In particular, mailing-list software often ships mail with only
2127 the list broadcast address in the To header.
2129 .B Note that a future version of fetchmail may remove To/Cc parsing!
2133 cannot deduce a recipient address that is local, and the intended
2134 recipient address was anyone other than fetchmail's invoking user,
2135 .B mail will get lost.
2136 This is what makes the multidrop feature risky without proper envelope
2139 A related problem is that when you blind-copy a mail message, the Bcc
2140 information is carried \fIonly\fR as envelope address (it's removed from
2141 the headers by the sending mail server, so fetchmail can see it only if
2142 there is an X-Envelope-To header). Thus, blind-copying to someone who
2143 gets mail over a fetchmail multidrop link will fail unless the the
2144 mailserver host routinely writes X-Envelope-To or an equivalent header
2145 into messages in your maildrop.
2147 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2148 server you're fetching from (1) stores one copy of the message per
2149 recipient in \fBIyour\fP domain and (2) records the envelope
2150 information in a special header (X-Original-To, Delivered-To,
2153 .SS Good Ways To Use Multidrop Mailboxes
2154 Multiple local names can be used to administer a mailing list from the
2155 client side of a \fIfetchmail\fR collection. Suppose your name is
2156 \&'esr', and you want to both pick up your own mail and maintain a mailing
2157 list called (say) "fetchmail-friends", and you want to keep the alias
2158 list on your client machine.
2160 On your server, you can alias \&'fetchmail-friends' to 'esr'; then, in
2161 your \fI.fetchmailrc\fR, declare \&'to esr fetchmail-friends here'.
2162 Then, when mail including 'fetchmail-friends' as a local address
2163 gets fetched, the list name will be appended to the list of
2164 recipients your SMTP listener sees. Therefore it will undergo alias
2165 expansion locally. Be sure to include 'esr' in the local alias
2166 expansion of fetchmail-friends, or you'll never see mail sent only to
2167 the list. Also be sure that your listener has the "me-too" option set
2168 (sendmail's -oXm command-line option or OXm declaration) so your name
2169 isn't removed from alias expansions in messages you send.
2171 This trick is not without its problems, however. You'll begin to see
2172 this when a message comes in that is addressed only to a mailing list
2173 you do \fInot\fR have declared as a local name. Each such message
2174 will feature an 'X-Fetchmail-Warning' header which is generated
2175 because fetchmail cannot find a valid local name in the recipient
2176 addresses. Such messages default (as was described above) to being
2177 sent to the local user running
2179 but the program has no way to know that that's actually the right thing.
2181 .SS Bad Ways To Abuse Multidrop Mailboxes
2182 Multidrop mailboxes and
2184 serving multiple users in daemon mode do not mix. The problem, again, is
2185 mail from mailing lists, which typically does not have an individual
2186 recipient address on it. Unless
2188 can deduce an envelope address, such mail will only go to the account
2189 running fetchmail (probably root). Also, blind-copied users are very
2190 likely never to see their mail at all.
2192 If you're tempted to use
2194 to retrieve mail for multiple users from a single mail drop via POP or
2195 IMAP, think again (and reread the section on header and envelope
2196 addresses above). It would be smarter to just let the mail sit in the
2197 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2198 SMTP sends periodically (of course, this means you have to poll more
2199 frequently than the mailserver's expiry period). If you can't arrange
2200 this, try setting up a UUCP feed.
2202 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2203 your mailserver writes an envelope-address header that fetchmail can
2204 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2207 .SS Speeding Up Multidrop Checking
2208 Normally, when multiple users are declared
2210 extracts recipient addresses as described above and checks each host
2211 part with DNS to see if it's an alias of the mailserver. If so, the
2212 name mappings described in the "to ... here" declaration are done and
2213 the mail locally delivered.
2215 This is a convenient but also slow method. To speed
2216 it up, pre-declare mailserver aliases with 'aka'; these are checked
2217 before DNS lookups are done. If you're certain your aka list contains
2219 DNS aliases of the mailserver (and all MX names pointing at it - note
2220 this may change in a future version)
2221 you can declare 'no dns' to suppress DNS lookups entirely and
2222 \fIonly\fR match against the aka list.
2225 To facilitate the use of
2227 in shell scripts, an exit code is returned to give an indication
2228 of what occurred during a given connection.
2230 The exit codes returned by
2234 One or more messages were successfully retrieved (or, if the -c option
2235 was selected, were found waiting but not retrieved).
2237 There was no mail awaiting retrieval. (There may have been old mail still
2238 on the server but not selected for retrieval.)
2240 An error was encountered when attempting to open a socket to retrieve
2241 mail. If you don't know what a socket is, don't worry about it --
2242 just treat this as an 'unrecoverable error'. This error can also be
2243 because a protocol fetchmail wants to use is not listed in /etc/services.
2245 The user authentication step failed. This usually means that a bad
2246 user-id, password, or APOP id was specified. Or it may mean that you
2247 tried to run fetchmail under circumstances where it did not have
2248 standard input attached to a terminal and could not prompt for a
2251 Some sort of fatal protocol error was detected.
2253 There was a syntax error in the arguments to
2256 The run control file had bad permissions.
2258 There was an error condition reported by the server. Can also
2261 timed out while waiting for the server.
2263 Client-side exclusion error. This means
2265 either found another copy of itself already running, or failed in such
2266 a way that it isn't sure whether another copy is running.
2268 The user authentication step failed because the server responded "lock
2269 busy". Try again after a brief pause! This error is not implemented
2270 for all protocols, nor for all servers. If not implemented for your
2271 server, "3" will be returned instead, see above. May be returned when
2272 talking to qpopper or other servers that can respond with "lock busy"
2273 or some similar text containing the word "lock".
2277 run failed while trying to do an SMTP port open or transaction.
2279 Fatal DNS error. Fetchmail encountered an error while performing
2280 a DNS lookup at startup and could not proceed.
2282 BSMTP batch file could not be opened.
2284 Poll terminated by a fetch limit (see the --fetchlimit option).
2286 Server busy indication.
2288 Server timed out during an IMAP IDLE.
2290 Internal error. You should see a message on standard error with
2295 queries more than one host, return status is 0 if \fIany\fR query
2296 successfully retrieved mail. Otherwise the returned error status is
2297 that of the last host queried.
2302 default run control file
2305 default location of file associating hosts with last message IDs seen
2306 (used only with newer RFC1939-compliant POP3 servers supporting the
2310 lock file to help prevent concurrent runs (non-root mode).
2313 your FTP run control file, which (if present) will be searched for
2314 passwords as a last resort before prompting for one interactively.
2316 /var/run/fetchmail.pid
2317 lock file to help prevent concurrent runs (root mode, Linux systems).
2320 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2323 If the FETCHMAILUSER variable is set, it is used as the name of the
2324 calling user (default local name) for purposes such as mailing error
2325 notifications. Otherwise, if either the LOGNAME or USER variable is
2326 correctly set (e.g. the corresponding UID matches the session user ID)
2327 then that name is used as the default local name. Otherwise
2328 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2329 session ID (this elaborate logic is designed to handle the case of
2330 multiple names per userid gracefully).
2332 If the environment variable FETCHMAILHOME is set to a valid and
2333 existing directory name, the .fetchmailrc and .fetchids and
2334 \&.fetchmail.pid files are put there instead of in the invoking user's
2335 home directory (and lose the leading dots on their names). The
2336 \&.netrc file is looked for in the the invoking user's home directory
2337 regardless of FETCHMAILHOME's setting.
2339 If the HOME_ETC variable is set, file $HOME_ETC/.fetchmailrc is used
2340 instead of ~/.fetchmailrc.
2345 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2346 forces a poll of all non-skipped servers (this is in accordance with
2347 the usual conventions for system daemons).
2351 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2352 so SIGHUP due to logout can retain the default action of killing it).
2356 in foreground while a background fetchmail is running will do
2357 whichever of these is appropriate to wake it up.
2359 .SH BUGS AND KNOWN PROBLEMS
2361 The assumptions that the DNS and in particular the checkalias options
2362 make are not often sustainable. For instance, it has become uncommon for
2363 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2364 MX lookups may go away in a future release.
2366 The mda and plugin options interact badly. In order to collect error
2367 status from the MDA, fetchmail has to change its normal signal
2368 handling so that dead plugin processes don't get reaped until the end
2369 of the poll cycle. This can cause resource starvation if too many
2370 zombies accumulate. So either don't deliver to a MDA using plugins or
2371 risk being overrun by an army of undead.
2373 The --interface option does not support IPv6 and it is doubtful if it
2374 ever will, since there is no portable way to query interface IPv6
2377 The RFC822 address parser used in multidrop mode chokes on some
2378 @-addresses that are technically legal but bizarre. Strange uses of
2379 quoting and embedded comments are likely to confuse it.
2381 In a message with multiple envelope headers, only the last one
2382 processed will be visible to fetchmail. To get around this, use a
2383 mailserver-side filter that consolidates the contents of all envelope
2384 headers into a single one (procmail, mailagent, or maildrop can be
2385 programmed to do this fairly easily).
2387 Use of some of these protocols requires that the program send
2388 unencrypted passwords over the TCP/IP connection to the mailserver.
2389 This creates a risk that name/password pairs might be snaffled with a
2390 packet sniffer or more sophisticated monitoring software. Under Linux
2391 and FreeBSD, the --interface option can be used to restrict polling to
2392 availability of a specific interface device with a specific local or
2393 remote IP address, but snooping is still possible if (a) either host
2394 has a network device that can be opened in promiscuous mode, or (b)
2395 the intervening network link can be tapped. We recommend the use of
2397 tunnelling to not only shroud your passwords but encrypt the entire
2400 Use of the %F or %T escapes in an mda option could open a security
2401 hole, because they pass text manipulable by an attacker to a shell
2402 command. Potential shell characters are replaced by '_' before
2403 execution. The hole is further reduced by the fact that fetchmail
2404 temporarily discards any suid privileges it may have while running the
2405 MDA. For maximum safety, however, don't use an mda command containing
2406 %F or %T when fetchmail is run from the root account itself.
2408 Fetchmail's method of sending bounces due to errors or spam-blocking and
2409 spam bounces requires that port 25 of localhost be available for sending
2414 while a background instance is running and break the syntax, the
2415 background instance will die silently. Unfortunately, it can't
2416 die noisily because we don't yet know whether syslog should be enabled.
2417 On some systems, fetchmail dies quietly even if there is no syntax
2418 error; this seems to have something to do with buggy terminal ioctl
2421 The -f - option (reading a configuration from stdin) is incompatible
2422 with the plugin option.
2424 The 'principal' option only handles Kerberos IV, not V.
2426 Interactively entered passwords are truncated after 63 characters. If
2427 you really need to use a longer password, you will have to use a
2430 Send comments, bug reports, gripes, and the like to the
2431 fetchmail-devel list <fetchmail-devel@lists.berlios.de>. An HTML FAQ is
2432 available at the fetchmail home page; surf to
2433 http://fetchmail.berlios.de/ or do a WWW search for pages with
2434 \&'fetchmail' in their titles.
2437 Eric S. Raymond <esr@snark.thyrsus.com>. Too many other people to
2438 name here have contributed code and patches.
2439 This program is descended from and replaces
2441 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2442 but some of its interface design is directly traceable to that
2445 This manual page has been improved by R.\ Hannes Beinert.
2447 Fetchmail is currently maintained by Matthias Andree and Rob Funk.
2450 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2451 .SH APPLICABLE STANDARDS
2454 RFC 821, RFC2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2458 RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.
2464 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC1734, RFC 1939, RFC 1957,
2468 RFC 1460, RFC 1725, RFC 1939.
2477 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
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