2 .\" ** The above line should force tbl to be used as a preprocessor **
4 .\" Man page for fetchmail
6 .\" For license terms, see the file COPYING in this directory.
9 fetchmail \- fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
12 \fBfetchmail\fR [\fIoption...\fR] [\fImailserver...\fR]
18 is a mail-retrieval and forwarding utility; it fetches mail from
19 remote mailservers and forwards it to your local (client) machine's
20 delivery system. You can then handle the retrieved mail using normal
21 mail user agents such as \fImutt\fR(1), \fIelm\fR(1) or \fIMail\fR(1).
22 The \fIfetchmail\fR utility can be run in a daemon mode to repeatedly
23 poll one or more systems at a specified interval.
27 program can gather mail from servers supporting any of the common
28 mail-retrieval protocols: POP2, POP3, IMAP2bis, IMAP4, and IMAP4rev1.
29 It can also use the ESMTP ETRN extension and ODMR. (The RFCs describing all
30 these protocols are listed at the end of this manual page.)
34 is primarily intended to be used over on-demand TCP/IP links (such as
35 SLIP or PPP connections), it may also be useful as a message transfer
36 agent for sites which refuse for security reasons to permit
37 (sender-initiated) SMTP transactions with sendmail.
41 is used with a POP or an IMAP server, it has two fundamental modes of
42 operation for each user account from which it retrieves mail:
43 \fIsingledrop\fR- and \fImultidrop\fR-mode. In singledrop-mode,
45 assumes that all messages in the user's account are intended for a single
46 recipient. An individual mail message will not be inspected for recipient
47 information, rather, the identity of the recipient will either default to
48 the local user currently executing \fIfetchmail\fR,
49 or else will need to be explicitly specified in the configuration file.
50 Singledrop-mode is used when the fetchmailrc configuration contains at
51 most a single local user specification for a given server account.
55 is not able to assume that there is only a single recipient, but rather
56 that the mail server account actually contains mail intended for any
57 number of different recipients. Therefore,
59 must attempt to deduce the proper "envelope recipient" from the mail
60 headers of each message. In this mode of operation
62 almost resembles an MTA, however it is important to note that neither
63 the POP nor IMAP protocols were intended for use in this fashion, and
64 hence envelope information is not directly available. Instead,
66 must resort to a process of informed guess-work in an attempt to
67 discover the true envelope recipient of a message. Even if this
68 information is present in the headers, the process can
69 be error-prone and is dependent upon the specific mail server used
70 for mail retrieval. Multidrop-mode is used when more than one local
71 user is specified for a particular server account in the configuration
72 file. Note that the forgoing discussion of singledrop- and
73 multidrop-modes does not apply to the ESMTP ETRN or ODMR retrieval
74 methods, since they are based upon the SMTP protocol which
75 specifically provides the envelope recipient to \fIfetchmail\fR.
77 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
78 port 25 on the machine it is running on (localhost), just as though it
79 were being passed in over a normal TCP/IP link. \fIfetchmail\fR provides
80 the SMTP server with an envelope recipient derived in the manner described
81 previously. The mail will then be
82 delivered locally via your system's MDA (Mail Delivery Agent, usually
83 \fIsendmail\fR(8) but your system may use a different one such
84 as \fIsmail\fR, \fImmdf\fR, \fIexim\fR, \fIpostfix\fR, or \fIqmail\fR). All the
85 delivery-control mechanisms (such as \fI.forward\fR files) normally
86 available through your system MDA and local delivery agents will
87 therefore work automatically.
89 If no port 25 listener is available, but your fetchmail configuration
90 was told about a reliable local MDA, it will use that MDA for local
91 delivery instead. At build time, fetchmail normally looks for
100 is available, it will assist you in setting up and editing a
101 fetchmailrc configuration. It runs under X and requires that the
102 language Python and the Tk toolkit be present on your system. If
103 you are first setting up fetchmail for single-user mode, it is
104 recommended that you use Novice mode. Expert mode provides
105 complete control of fetchmail configuration, including the
106 multidrop features. In either case, the `Autoprobe' button
107 will tell you the most capable protocol a given mailserver
108 supports, and warn you of potential problems with that server.
110 .SH GENERAL OPERATION
113 is controlled by command-line options and a run control file,
114 .IR ~/.fetchmailrc\fR ,
115 the syntax of which we describe in a later section (this file is what
116 the \fIfetchmailconf\fR program edits). Command-line options override
120 Each server name that you specify following the options on the
121 command line will be queried. If you don't specify any servers
122 on the command line, each `poll' entry in your
124 file will be queried.
126 To facilitate the use of
128 in scripts and pipelines, it returns an appropriate exit code upon
129 termination -- see EXIT CODES below.
131 The following options modify the behavior of \fIfetchmail\fR. It is
132 seldom necessary to specify any of these once you have a
133 working \fI.fetchmailrc\fR file set up.
135 Almost all options have a corresponding keyword which can be used to
140 Some special options are not covered here, but are documented instead
141 in sections on AUTHENTICATION and DAEMON MODE which follow.
145 Displays the version information for your copy of
147 No mail fetch is performed.
148 Instead, for each server specified, all the option information
149 that would be computed if
151 were connecting to that server is displayed. Any non-printables in
152 passwords or other string names are shown as backslashed C-like
153 escape sequences. This option is useful for verifying that your
154 options are set the way you want them.
157 Return a status code to indicate whether there is mail waiting,
158 without actually fetching or deleting mail (see EXIT CODES below).
159 This option turns off daemon mode (in which it would be useless). It
160 doesn't play well with queries to multiple sites, and doesn't work
161 with ETRN or ODMR. It will return a false positive if you leave read but
162 undeleted mail in your server mailbox and your fetch protocol can't
163 tell kept messages from new ones. This means it will work with IMAP,
164 not work with POP2, and may occasionally flake out under POP3.
167 Silent mode. Suppresses all progress/status messages that are
168 normally echoed to standard output during a fetch (but does not
169 suppress actual error messages). The --verbose option overrides this.
172 Verbose mode. All control messages passed between
174 and the mailserver are echoed to stdout. Overrides --silent.
175 Doubling this option (-v -v) causes extra diagnostic information
181 Retrieve both old (seen) and new messages from the mailserver. The
182 default is to fetch only messages the server has not marked seen.
183 Under POP3, this option also forces the use of RETR rather than TOP.
184 Note that POP2 retrieval behaves as though --all is always on (see
185 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN
190 Keep retrieved messages on the remote mailserver. Normally, messages
191 are deleted from the folder on the mailserver after they have been retrieved.
194 option causes retrieved messages to remain in your folder on the
195 mailserver. This option does not work with ETRN or ODMR.
199 Delete retrieved messages from the remote mailserver. This
200 option forces retrieved mail to be deleted. It may be useful if
201 you have specified a default of \fBkeep\fR in your
202 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
205 POP3/IMAP only. Delete old (previously retrieved) messages from the
206 mailserver before retrieving new messages. This option does not work
207 with ETRN or ODMR. Warning: if your local MTA hangs and fetchmail is
208 aborted, the next time you run fetchmail, it will delete mail that was
209 never delivered to you. What you probably want is the default
210 setting: if you don't specify `-k', then fetchmail will automatically
211 delete messages after successful delivery.
212 .SS Protocol and Query Options
214 .B \-p <proto> | \-\-protocol <proto>
215 (Keyword: proto[col])
216 Specify the protocol to use when communicating with the remote
217 mailserver. If no protocol is specified, the default is AUTO.
219 may be one of the following:
222 Tries IMAP, POP3, and POP2 (skipping any of these for which support
223 has not been compiled in).
225 Post Office Protocol 2
227 Post Office Protocol 3
229 Use POP3 with old-fashioned MD5-challenge authentication.
231 Use POP3 with RPOP authentication.
233 Use POP3 with Kerberos V4 authentication on port 1109.
235 Use POP3 with Demon Internet's SDPS extensions.
237 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
239 Use the ESMTP ETRN option.
241 Use the the On-Demand Mail Relay ESMTP profile.
244 All these alternatives work in basically the same way (communicating
245 with standard server daemons to fetch mail already delivered to a
246 mailbox on the server) except ETRN and ODMR. The ETRN mode
247 allows you to ask a compliant ESMTP server (such as BSD sendmail at
248 release 8.8.0 or higher) to immediately open a sender-SMTP connection
249 to your client machine and begin forwarding any items addressed to
250 your client machine in the server's queue of undelivered mail. The
251 ODMR mode requires an ODMR-capable server and works similarly to
252 ETRN, except that it does not require the client machine to have
257 Force UIDL use (effective only with POP3). Force client-side tracking
258 of `newness' of messages (UIDL stands for ``unique ID listing'' and is
259 described in RFC1725). Use with `keep' to use a mailbox as a baby
260 news drop for a group of users. The fact that seen messages are skipped
261 is logged, unless error logging is done through syslog while running in
265 .B \-P <portnumber> | \-\-port <portnumber>
267 The port option permits you to specify a TCP/IP port to connect on.
268 This option will seldom be necessary as all the supported protocols have
269 well-established default port numbers.
271 .B \-\-principal <principal>
273 The principal option permits you to specify a service principal for
274 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
277 .B \-t <seconds> | -\-timeout <seconds>
279 The timeout option allows you to set a server-nonresponse
280 timeout in seconds. If a mailserver does not send a greeting message
281 or respond to commands for the given number of seconds,
282 \fIfetchmail\fR will hang up on it. Without such a timeout
283 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
284 down host. This would be particularly annoying for a \fIfetchmail\fR
285 running in background. There is a default timeout which fetchmail -V
286 will report. If a given connection receives too many timeouts in
287 succession, fetchmail will consider it wedged and stop retrying,
288 the calling user will be notified by email if this happens.
290 .B \-\-plugin <command>
291 (Keyword: plugin) The plugin option allows you to use an external
292 program to establish the TCP connection. This is useful if you want
293 to use socks, SSL, ssh, or need some special firewalling setup. The
294 program will be looked up in $PATH and can optionally be passed the
295 hostname and port as arguments using "%h" and "%p" respectively (note
296 that the interpolation logic is rather primitive, and these token must
297 be bounded by whitespace or beginning of string or end of string).
298 Fetchmail will write to the plugin's stdin and read from the plugin's
301 .B \-\-plugout <command>
303 Identical to the plugin option above, but this one is used for the SMTP
304 connections (which will probably not need it, so it has been separated
307 .B \-r <name> | \-\-folder <name>
309 Causes a specified non-default mail folder on the mailserver (or
310 comma-separated list of folders) to be retrieved. The syntax of the
311 folder name is server-dependent. This option is not available under
315 (Keyword: tracepolls)
316 Tell fetchmail to poll trace information in the form `polling %s
317 account %s' to the Received line it generates, where the %s parts are
318 replaced by the user's remote name and the poll label (the Received
319 header also normally includes the server's true name). This can be
320 used to facilitate mail filtering based on the account it is being
325 Causes the connection to the mail server to be encrypted via SSL. Connect
326 to the server using the specified base protocol over a connection secured
327 by SSL. SSL support must be present at the server. If no port is
328 specified, the connection is attempted to the well known port of the SSL
329 version of the base protocol. This is generally a different port than the
330 port used by the base protocol. For IMAP, this is port 143 for the clear
331 protocol and port 993 for the SSL secured protocol.
333 .B \-\-sslcert <name>
335 Specifies the file name of the client side public SSL certificate. Some
336 SSL encrypted servers may require client side keys and certificates for
337 authentication. In most cases, this is optional. This specifies
338 the location of the public key certificate to be presented to the server
339 at the time the SSL session is established. It is not required (but may
340 be provided) if the server does not require it. Some servers may
341 require it, some servers may request it but not require it, and some
342 servers may not request it at all. It may be the same file
343 as the private key (combined key and certificate file) but this is not
348 Specifies the file name of the client side private SSL key. Some SSL
349 encrypted servers may require client side keys and certificates for
350 authentication. In most cases, this is optional. This specifies
351 the location of the private key used to sign transactions with the server
352 at the time the SSL session is established. It is not required (but may
353 be provided) if the server does not require it. Some servers may
354 require it, some servers may request it but not require it, and some
355 servers may not request it at all. It may be the same file
356 as the public key (combined key and certificate file) but this is not
357 recommended. If a password is required to unlock the key, it will be
358 prompted for at the time just prior to establishing the session to the
359 server. This can cause some complications in daemon mode.
361 .B \-\-sslproto <name>
363 Forces an SSL protocol. Possible values are \&`\fBssl2\fR', `\fBssl3\fR' and
364 `\fBtls1\fR'. Try this if the default handshake does not work for your server.
368 Causes fetchmail to strictly check the server certificate against a set of
369 local trusted certificates (see the \fBsslcertpath\fR option). If the server
370 certificate is not signed by one of the trusted ones (directly or indirectly),
371 the SSL connection will fail. This checking should prevent man-in-the-middle
372 attacks against the SSL connection. Note that CRLs are seemingly not currently
373 supported by OpenSSL in certificate verification! Your system clock should
374 be reasonably accurate when using this option!
376 .B \-\-sslcertpath <directory>
377 (Keyword: sslcertpath)
378 Sets the directory fetchmail uses to look up local certificates. The default
379 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
380 it - every time you add or modify a certificate in the directory, you need
381 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
384 .B \-\-sslfingerprint <fingerprint>
385 (Keyword: sslfingerprint)
386 Specify the fingerprint of the server key (an MD5 hash of the key) in
387 hexadecimal notation with colons separating groups of two digits. The letter
388 hex digits must be in upper case. This is the default format OpenSSL uses,
389 and the one fetchmail uses to report the fingerprint when an SSL connection
390 is established. When this is specified, fetchmail will compare the server key
391 fingerprint with the given one, and the connection will fail if they do not
392 match. This can be used to prevent man-in-the-middle attacks.
393 .SS Delivery Control Options
395 .B \-S <hosts> | \-\-smtphost <hosts>
396 (Keyword: smtp[host])
397 Specify a hunt list of hosts to forward mail to (one or more
398 hostnames, comma-separated). Hosts are tried in list order; the first
399 one that is up becomes the forwarding target for the current run.
400 Normally, `localhost' is added to the end of the list as an invisible
401 default. However, when using Kerberos authentication, the FQDN of the
402 machine running fetchmail is added to the end of the list as an
403 invisible default. Each hostname may have a port number following the
404 host name. The port number is separated from the host name by a
405 slash; the default port is 25 (or ``smtp'' under IPv6). If you
406 specify an absolute path name (beginning with a /), it will be
407 interpreted as the name of a UNIX socket accepting LMTP connections
408 (such as is supported by the Cyrus IMAP daemon) Example:
411 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
414 This option can be used with ODMR, and will make fetchmail a relay
415 between the ODMR server and SMTP or LMTP receiver.
417 .B \-\-fetchdomains <hosts>
418 (Keyword: fetchdomains)
419 In ETRN or ODMR mode, this option specifies the list of domains the
420 server should ship mail for once the connection is turned around. The
421 default is the FQDN of the machine running
424 .B \-D <domain> | \-\-smtpaddress <domain>
425 (Keyword: smtpaddress) Specify the domain to be appended to addresses
426 in RCPT TO lines shipped to SMTP. The name of the SMTP server (as
427 specified by --smtphost, or defaulted to "localhost") is used when
428 this is not specified.
430 .B \-\-smtpname <user@domain>
432 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
433 The default user is the current local user.
435 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
437 Specifies the list of numeric SMTP errors that are to be interpreted
438 as a spam-block response from the listener. A value of -1 disables
439 this option. For the command-line option, the list values should
442 .B \-m <command> | \-\-mda <command>
443 (Keyword: mda) You can force mail to be passed to an MDA directly
444 (rather than forwarded to port 25) with the --mda or -m option. To
445 avoid losing mail, use this option only with MDAs like procmail or
446 sendmail that return a nonzero status on disk-full and other
447 resource-exhaustion errors; the nonzero status tells fetchmail that
448 delivery failed and prevents the message from being deleted off the
449 server. If \fIfetchmail\fR is running as root, it sets its user id to
450 that of the target user while delivering mail through an MDA. Some
451 possible MDAs are "/usr/sbin/sendmail -i -f %F %T", "/usr/bin/deliver"
452 and "/usr/bin/procmail -d %T" (but the latter is usually redundant as
453 it's what SMTP listeners normally forward to). Local delivery
454 addresses will be inserted into the MDA command wherever you place a
455 %T; the mail message's From address will be inserted where you place
456 an %F. In both cases the addresses are enclosed in single quotes ('),
457 after removing any single quotes they may contain, before the MDA
458 command is passed to the shell. Do \fInot\fR use an MDA invocation
459 like "sendmail -i -t" that dispatches on the contents of To/Cc/Bcc, it
460 will create mail loops and bring the just wrath of many postmasters
461 down upon your head. Also, do \fInot\fR try to combine multidrop
462 mode with an MDA such as procmail that can only accept one addressee;
467 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
468 port \fImust\fR be explicitly specified (with a slash suffix) on each
469 host in the smtphost hunt list if this option is selected; the
470 default port 25 will (in accordance with RFC 2033) not be accepted.
472 .B \-\-bsmtp <filename>
474 Append fetched mail to a BSMTP file. This simply contains the SMTP
475 commands that would normally be generated by fetchmail when passing
476 mail to an SMTP listener daemon. An argument of `-' causes the mail
477 to be written to standard output. Note that fetchmail's
478 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
479 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
480 MAILBOXES below apply.
481 .SS Resource Limit Control Options
483 .B \-l <maxbytes> | \-\-limit <maxbytes>
484 (Keyword: limit) Takes a maximum octet size argument. Messages larger
485 than this size will not be fetched and will be left on the server (in
486 foreground sessions, the progress messages will note that they are
487 "oversized"). If the fetch protocol permits (in particular, under
488 IMAP or POP3 without the fetchall option) the message will not be
489 marked seen. An explicit --limit of 0 overrides any limits set in your
490 run control file. This option is intended for those needing to
491 strictly control fetch time due to expensive and variable phone rates.
492 Combined with --flush, it can be used to delete oversized messages
493 waiting on a server. In daemon mode, oversize notifications are
494 mailed to the calling user (see the --warnings option). This option
495 does not work with ETRN or ODMR.
497 .B \-w <interval> | \-\-warnings <interval>
499 Takes an interval in seconds. When you call
501 with a `limit' option in daemon mode, this controls the interval at
502 which warnings about oversized messages are mailed to the calling user
503 (or the user specified by the `postmaster' option). One such
504 notification is always mailed at the end of the the first poll that
505 the oversized message is detected. Thereafter, renotification is
506 suppressed until after the warning interval elapses (it will take
507 place at the end of the first following poll).
509 .B \-b <count> | \-\-batchlimit <count>
510 (Keyword: batchlimit)
511 Specify the maximum number of messages that will be shipped to an SMTP
512 listener before the connection is deliberately torn down and rebuilt
513 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
514 overrides any limits set in your run control file. While
515 \fBsendmail\fR(8) normally initiates delivery of a message immediately
516 after receiving the message terminator, some SMTP listeners are not so
517 prompt. MTAs like \fIsmail\fR(8) may wait till the
518 delivery socket is shut down to deliver. This may produce annoying
519 delays when \fIfetchmail\fR is processing very large batches. Setting
520 the batch limit to some nonzero size will prevent these delays. This
521 option does not work with ETRN or ODMR.
523 .B \-B <number> | \-\-fetchlimit <number>
524 (Keyword: fetchlimit)
525 Limit the number of messages accepted from a given server in a single
526 poll. By default there is no limit. An explicit --fetchlimit of 0
527 overrides any limits set in your run control file.
528 This option does not work with ETRN or ODMR.
530 .B \-\-fetchsizelimit <number>
531 (Keyword: fetchsizelimit)
532 Limit the number of sizes of messages accepted from a given server in
533 a single transaction. This option is useful in reducing the delay in
534 downloading the first mail when there are too many mails in the
535 mailbox. By default, the limit is 100. If set to 0, sizes of all
536 messages are downloaded at the start.
537 This option does not work with ETRN or ODMR. For POP3, the only valid
540 .B \-\-fastuidl <number>
542 Do a binary instead of linear search for the first unseen UID. Binary
543 search avoids downloading the UIDs of all mails. This saves time
544 (especially in daemon mode) where downloading the same set of UIDs in
545 each poll is a waste of bandwidth. The number `n' indicates how rarely
546 a linear search should be done. In daemon mode, linear search is used
547 once followed by binary searches in `n-1' polls if `n' is greater than
548 1; binary search is always used if `n' is 1; linear search is always
549 used if `n' is 0. In non-daemon mode, binary search is used if `n' is
550 1; otherwise linear search is used.
551 This option works with POP3 only.
553 .B \-e <count> | \-\-expunge <count>
555 Arrange for deletions to be made final after a given number of
556 messages. Under POP2 or POP3, fetchmail cannot make deletions final
557 without sending QUIT and ending the session -- with this option on,
558 fetchmail will break a long mail retrieval session into multiple
559 sub-sessions, sending QUIT after each sub-session. This is a good
560 defense against line drops on POP3 servers that do not do the
561 equivalent of a QUIT on hangup. Under IMAP,
563 normally issues an EXPUNGE command after each deletion in order to
564 force the deletion to be done immediately. This is safest when your
565 connection to the server is flaky and expensive, as it avoids
566 resending duplicate mail after a line hit. However, on large
567 mailboxes the overhead of re-indexing after every message can slam the
568 server pretty hard, so if your connection is reliable it is good to do
569 expunges less frequently. Also note that some servers enforce a delay
570 of a few seconds after each quit, so fetchmail may not be able to get
571 back in immediately after an expunge -- you may see "lock busy" errors
572 if this happens. If you specify this option to an integer N,
575 to only issue expunges on every Nth delete. An argument of zero
576 suppresses expunges entirely (so no expunges at all will be done until
577 the end of run). This option does not work with ETRN or ODMR.
578 .SS Authentication Options
580 .B \-u <name> | \-\-username <name>
581 (Keyword: user[name])
582 Specifies the user identification to be used when logging in to the mailserver.
583 The appropriate user identification is both server and user-dependent.
584 The default is your login name on the client machine that is running
586 See USER AUTHENTICATION below for a complete description.
588 .B \-I <specification> | \-\-interface <specification>
590 Require that a specific interface device be up and have a specific local
591 or remote IP address (or range) before polling. Frequently
593 is used over a transient point-to-point TCP/IP link established directly
594 to a mailserver via SLIP or PPP. That is a relatively secure channel.
595 But when other TCP/IP routes to the mailserver exist (e.g. when the link
596 is connected to an alternate ISP), your username and password may be
597 vulnerable to snooping (especially when daemon mode automatically polls
598 for mail, shipping a clear password over the net at predictable
599 intervals). The --interface option may be used to prevent this. When
600 the specified link is not up or is not connected to a matching IP
601 address, polling will be skipped. The format is:
604 interface/iii.iii.iii.iii/mmm.mmm.mmm.mmm
607 The field before the first slash is the interface name (i.e. sl0, ppp0
608 etc.). The field before the second slash is the acceptable IP address.
609 The field after the second slash is a mask which specifies a range of
610 IP addresses to accept. If no mask is present 255.255.255.255 is
611 assumed (i.e. an exact match). This option is currently only supported
612 under Linux and FreeBSD. Please see the
614 section for below for FreeBSD specific information.
616 .B \-M <interface> | --monitor <interface>
618 Daemon mode can cause transient links which are automatically taken down
619 after a period of inactivity (e.g. PPP links) to remain up
620 indefinitely. This option identifies a system TCP/IP interface to be
621 monitored for activity. After each poll interval, if the link is up but
622 no other activity has occurred on the link, then the poll will be
623 skipped. However, when fetchmail is woken up by a signal, the
624 monitor check is skipped and the poll goes through unconditionally.
625 This option is currently only supported under Linux and FreeBSD.
630 options to work for non root users under FreeBSD, the fetchmail binary
631 must be installed SGID kmem. This would be a security hole, but
632 fetchmail runs with the effective GID set to that of the kmem group
634 when interface data is being collected.
637 (Keyword: auth[enticate])
638 This option permits you to specify an authentication type (see USER
639 AUTHENTICATION below for details). The possible values are \fBany\fR,
640 \&`\fBpassword\fR', `\fBkerberos_v5\fR' and `\fBkerberos\fR' (or, for
641 excruciating exactness, `\fBkerberos_v4\fR'), \fRgssapi\fR,
642 \fIcram-md5\fR, \fIotp\fR, \fIntlm\fR, and \fBssh\fR. When \fBany\fR (the
643 default) is specified, fetchmail tries first methods that don't
644 require a password (GSSAPI, KERBEROS_IV); then it looks for methods
645 that mask your password (CRAM-MD5, X-OTP, NTLM); and only if the server
646 doesn't support any of those will it ship your password en clair.
647 Other values may be used to force various authentication methods
648 (\fBssh\fR suppresses authentication). Any value other than
649 \fIpassword\fR, \fIcram-md5\fR, \fIntlm\fR or \fIotp\fR suppresses fetchmail's
650 normal inquiry for a password. Specify \fIssh\fR when you are using
651 an end-to-end secure connection such as an ssh tunnel; specify
652 \fRgssapi\fR or \fBkerberos_v4\fR if you are using a protocol variant
653 that employs GSSAPI or K4. Choosing KPOP protocol automatically
654 selects Kerberos authentication. This option does not work with ETRN.
655 .SS Miscellaneous Options
657 .B \-f <pathname> | \-\-fetchmailrc <pathname>
658 Specify a non-default name for the
660 run control file. The pathname argument must be either "-" (a single
661 dash, meaning to read the configuration from standard input) or a
662 filename. Unless the --version option is also on, a named file
663 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
666 .B \-i <pathname> | \-\-idfile <pathname>
668 Specify an alternate name for the .fetchids file used to save POP3
671 .B \-n | \-\-norewrite
672 (Keyword: no rewrite)
675 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
676 fetched mail so that any mail IDs local to the server are expanded to
677 full addresses (@ and the mailserver hostname are appended). This enables
678 replies on the client to get addressed correctly (otherwise your
679 mailer might think they should be addressed to local users on the
680 client machine!). This option disables the rewrite. (This option is
681 provided to pacify people who are paranoid about having an MTA edit
682 mail headers and want to know they can prevent it, but it is generally
683 not a good idea to actually turn off rewrite.)
684 When using ETRN or ODMR, the rewrite option is ineffective.
686 .B \-E <line> | \-\-envelope <line>
687 (Keyword: envelope; Multidrop only)
688 This option changes the header
690 assumes will carry a copy of the mail's envelope address. Normally
691 this is `X-Envelope-To' but as this header is not standard, practice
692 varies. See the discussion of multidrop address handling below. As a
693 special case, `envelope "Received"' enables parsing of sendmail-style
694 Received lines. This is the default, and it should not be necessary
695 unless you have globally disabled Received parsing with `no envelope'
696 in the \fI.fetchmailrc\fR file.
698 .B \-Q <prefix> | \-\-qvirtual <prefix>
699 (Keyword: qvirtual; Multidrop only)
700 The string prefix assigned to this option will be removed from the user
701 name found in the header specified with the \fIenvelope\fR option
702 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
703 if either is applicable). This option is useful if you are using
705 to collect the mail for an entire domain and your ISP (or your mail
706 redirection provider) is using qmail.
707 One of the basic features of qmail is the
711 message header. Whenever qmail delivers a message to a local mailbox
712 it puts the username and hostname of the envelope recipient on this
713 line. The major reason for this is to prevent mail loops. To set up
714 qmail to batch mail for a disconnected site the ISP-mailhost will have
715 normally put that site in its `Virtualhosts' control file so it will
716 add a prefix to all mail addresses for this site. This results in mail
717 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
718 sent to 'username\&@\&userhost.userdom.dom.com' having a
719 \&`Delivered-To:' line of the form:
721 Delivered-To: mbox-userstr-username\&@\&userhost.userdom.dom.com
723 The ISP can make the 'mbox-userstr-' prefix anything they choose
724 but a string matching the user host name is likely.
725 By using the option `envelope Delivered-To:' you can make fetchmail reliably
726 identify the original envelope recipient, but you have to strip the
727 `mbox-userstr-' prefix to deliver to the correct user.
728 This is what this option is for.
733 file, interpret any command-line options specified, and dump a
734 configuration report to standard output. The configuration report is
735 a data structure assignment in the language Python. This option
736 is meant to be used with an interactive
742 .SH USER AUTHENTICATION AND ENCRYPTION
743 All modes except ETRN require authentication of the client to the server.
744 Normal user authentication in
746 is very much like the authentication mechanism of
748 The correct user-id and password depend upon the underlying security
749 system at the mailserver.
751 If the mailserver is a Unix machine on which you have an ordinary user
752 account, your regular login name and password are used with
754 If you use the same login name on both the server and the client machines,
755 you needn't worry about specifying a user-id with the
757 option \-\- the default behavior is to use your login name on the
758 client machine as the user-id on the server machine. If you use a
759 different login name on the server machine, specify that login name
762 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
767 fetchmail -u jsmith mailgrunt
769 The default behavior of
771 is to prompt you for your mailserver password before the connection is
772 established. This is the safest way to use
774 and ensures that your password will not be compromised. You may also specify
775 your password in your
777 file. This is convenient when using
779 in daemon mode or with scripts.
781 If you do not specify a password, and
783 cannot extract one from your
785 file, it will look for a
787 file in your home directory before requesting one interactively; if an
788 entry matching the mailserver is found in that file, the password will
789 be used. Fetchmail first looks for a match on poll name; if it finds none,
790 it checks for a match on via name. See the
792 man page for details of the syntax of the
794 file. (This feature may allow you to avoid duplicating password
795 information in more than one file.)
797 On mailservers that do not provide ordinary user accounts, your user-id and
798 password are usually assigned by the server administrator when you apply for
799 a mailbox on the server. Contact your server administrator if you don't know
800 the correct user-id and password for your mailbox account.
802 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
803 independent authentication using the
805 file on the mailserver side. Under this RPOP variant, a fixed
806 per-user ID equivalent to a password was sent in clear over a link to
807 a reserved port, with the command RPOP rather than PASS to alert the
808 server that it should do special checking. RPOP is supported
811 (you can specify `protocol RPOP' to have the program send `RPOP'
812 rather than `PASS') but its use is strongly discouraged. This
813 facility was vulnerable to spoofing and was withdrawn in RFC1460.
815 RFC1460 introduced APOP authentication. In this variant of POP3,
816 you register an APOP password on your server host (the program
817 to do this with on the server is probably called \fIpopauth\fR(8)). You
818 put the same password in your
822 logs in, it sends a cryptographically secure hash of your password and
823 the server greeting time to the server, which can verify it by
824 checking its authorization database.
826 If your \fIfetchmail\fR was built with Kerberos support and you specify
827 Kerberos authentication (either with --auth or the \fI.fetchmailrc\fR
828 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
829 ticket from the mailserver at the start of each query. Note: if
830 either the pollname or via name is `hesiod', fetchmail will try to use
831 Hesiod to look up the mailserver.
833 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
834 expect the server to have RFC1731- or RFC1734-conformant GSSAPI
835 capability, and will use it. Currently this has only been tested over
836 Kerberos V, so you're expected to already have a ticket-granting
837 ticket. You may pass a username different from your principal name
838 using the standard \fB--user\fR command or by the \fI.fetchmailrc\fR
841 If your IMAP daemon returns the PREAUTH response in its greeting line,
842 fetchmail will notice this and skip the normal authentication step.
843 This can be useful, e.g. if you start imapd explicitly using ssh.
844 In this case you can declare the authentication value `ssh' on that
845 site entry to stop \fI.fetchmail\fR from asking you for a password
848 If you are using POP3, and the server issues a one-time-password
849 challenge conforming to RFC1938, \fIfetchmail\fR will use your
850 password as a pass phrase to generate the required response. This
851 avoids sending secrets over the net unencrypted.
853 Compuserve's RPA authentication (similar to APOP) is supported. If you
854 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
855 authentication instead of sending over the password en clair if it
856 detects "@compuserve.com" in the hostname.
858 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
859 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
860 will try to perform an NTLM authentication (instead of sending over the
861 password en clair) whenever the server returns AUTH=NTLM in its
862 capability response. Specify a user option value that looks like
863 `user@domain': the part to the left of the @ will be passed as the
864 username and the part to the right as the NTLM domain.
866 If you are using IPsec, the -T (--netsec) option can be used to pass
867 an IP security request to be used when outgoing IP connections are
868 initialized. You can also do this using the `netsec' server option
869 in the .fetchmailrc file. In either case, the option value is a
870 string in the format accepted by the net_security_strtorequest()
871 function of the inet6_apps library.
873 You can access SSL encrypted services by specifying the --ssl option.
874 You can also do this using the "ssl" server option in the .fetchmailrc
875 file. With SSL encryption enabled, queries are initiated over a connection
876 after negotiating an SSL session. Some services, such as POP3 and IMAP,
877 have different well known ports defined for the SSL encrypted services.
878 The encrypted ports will be selected automatically when SSL is enabled and
879 no explicit port is specified.
881 When connecting to an SSL encrypted server, the server presents a certificate
882 to the client for validation. The certificate is checked to verify that
883 the common name in the certificate matches the name of the server being
884 contacted and that the effective and expiration dates in the certificate
885 indicate that it is currently valid. If any of these checks fail, a warning
886 message is printed, but the connection continues. The server certificate
887 does not need to be signed by any specific Certifying Authority and may
888 be a "self-signed" certificate.
890 Some SSL encrypted servers may request a client side certificate. A client
891 side public SSL certificate and private SSL key may be specified. If
892 requested by the server, the client certificate is sent to the server for
893 validation. Some servers may require a valid client certificate and may
894 refuse connections if a certificate is not provided or if the certificate
895 is not valid. Some servers may require client side certificates be signed
896 by a recognized Certifying Authority. The format for the key files and
897 the certificate files is that required by the underlying SSL libraries
898 (OpenSSL in the general case).
900 A word of care about the use of SSL: While above mentioned
901 setup with self-signed server certificates retrieved over the wires
902 can protect you from a passive eavesdropper it doesn't help against an
903 active attacker. It's clearly an improvement over sending the
904 passwords in clear but you should be aware that a man-in-the-middle
905 attack is trivially possible (in particular with tools such as dsniff,
906 http://www.monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
907 below for some examples) is preferable if you care seriously about the
908 security of your mailbox.
911 also supports authentication to the ESMTP server on the client side
912 according to RFC 2554. You can specify a name/password pair to be
913 used with the keywords `esmtpname' and `esmtppassword'; the former
914 defaults to the username of the calling user.
918 .B \-\-daemon <interval>
923 in daemon mode. You must specify a numeric argument which is a
924 polling interval in seconds.
928 puts itself in background and runs forever, querying each specified
929 host and then sleeping for the given polling interval.
935 will, therefore, poll all the hosts described in your
937 file (except those explicitly excluded with the `skip' verb) once
938 every fifteen minutes.
940 It is possible to set a polling interval
943 file by saying `set daemon <interval>', where <interval> is an
944 integer number of seconds. If you do this, fetchmail will always
945 start in daemon mode unless you override it with the command-line
946 option --daemon 0 or -d0.
948 Only one daemon process is permitted per user; in daemon mode,
950 makes a per-user lockfile to guarantee this.
952 Normally, calling fetchmail with a daemon in the background sends a
953 wake-up signal to the daemon, forcing it to poll mailservers
954 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
955 root, SIGUSR1 otherwise.) The wake-up action also clears any `wedged'
956 flags indicating that connections have wedged due to failed
957 authentication or multiple timeouts.
961 will kill a running daemon process instead of waking it up (if there
964 notifies you). If the --quit option is the only command-line option,
965 that's all there is to it.
967 The quit option may also be mixed with other command-line options; its
968 effect is to kill any running daemon before doing what the other
969 options specify in combination with the fetchmailrc file.
974 .B \-\-logfile <filename>
975 option (keyword: set logfile) allows you to redirect status messages
976 emitted while detached into a specified logfile (follow the
977 option with the logfile name). The logfile is opened for append, so
978 previous messages aren't deleted. This is primarily useful for
979 debugging configurations.
983 option (keyword: set syslog) allows you to redirect status and error
984 messages emitted to the
986 system daemon if available.
987 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
988 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
989 This option is intended for logging status and error messages which
990 indicate the status of the daemon and the results while fetching mail
992 Error messages for command line options and parsing the \fI.fetchmailrc\fR
993 file are still written to stderr, or to the specified log file.
996 option turns off use of
998 assuming it's turned on in the
1003 .B \-\-logfile <file>
1008 or --nodetach option suppresses backgrounding and detachment of the
1009 daemon process from its control terminal. This is primarily useful
1010 for debugging. Note that this also causes the logfile option to be
1011 ignored (though perhaps it shouldn't).
1013 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1014 transient errors (such as DNS failures or sendmail delivery refusals)
1015 may force the fetchall option on for the duration of the next polling
1016 cycle. This is a robustness feature. It means that if a message is
1017 fetched (and thus marked seen by the mailserver) but not delivered
1018 locally due to some transient error, it will be re-fetched during the
1019 next poll cycle. (The IMAP logic doesn't delete messages until
1020 they're delivered, so this problem does not arise.)
1022 If you touch or change the
1024 file while fetchmail is running in daemon mode, this will be detected
1025 at the beginning of the next poll cycle. When a changed
1027 is detected, fetchmail rereads it and restarts from scratch (using
1028 exec(2); no state information is retained in the new instance). Note also
1029 that if you break the
1031 file's syntax, the new instance will softly and silently vanish away
1034 .SH ADMINISTRATIVE OPTIONS
1037 .B \-\-postmaster <name>
1038 option (keyword: set postmaster) specifies the last-resort username to
1039 which multidrop mail is to be forwarded if no matching local recipient
1040 can be found. Normally this is just the user who invoked
1042 If the invoking user is root, then the default of this option is
1043 the user `postmaster'. Setting postmaster to the empty string causes
1044 such mail to be discarded.
1048 option suppresses the normal action of bouncing errors back to the
1049 sender in an RFC1894-conformant error message. If nobounce is on, the
1050 message will go to the postmaster instead.
1054 option (keyword: set invisible) tries to make fetchmail invisible.
1055 Normally, fetchmail behaves like any other MTA would -- it generates a
1056 Received header into each message describing its place in the chain of
1057 transmission, and tells the MTA it forwards to that the mail came from
1058 the machine fetchmail itself is running on. If the invisible option
1059 is on, the Received header is suppressed and fetchmail tries to spoof
1060 the MTA it forwards to into thinking it came directly from the
1065 option (keyword: set showdots) forces fetchmail to show progress dots
1066 even if the current tty is not stdout (for example logfiles).
1067 Starting with fetchmail version 5.3.0,
1068 progress dots are only shown on stdout by default.
1072 option, you can ask fetchmail to add information to the Received
1073 header on the form "polling {label} account {user}", where {label} is
1074 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1075 and {user} is the username which is used to log on to the mail
1076 server. This header can be used to make filtering email where no
1077 useful header information is available and you want mail from
1078 different accounts sorted into different mailboxes (this could, for
1079 example, occur if you have an account on the same server running a
1080 mailing list, and are subscribed to the list using that account). The
1081 default is not adding any such header. In
1083 this is called `tracepolls'.
1085 .SH RETRIEVAL FAILURE MODES
1086 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1087 bulletproof. In normal operation forwarding to port 25, no message is
1088 ever deleted (or even marked for deletion) on the host until the SMTP
1089 listener on the client side has acknowledged to \fIfetchmail\fR that
1090 the message has been either accepted for delivery or rejected due to a
1093 When forwarding to an MDA, however, there is more possibility
1094 of error. Some MDAs are `safe' and reliably return a nonzero status
1095 on any delivery error, even one due to temporary resource limits.
1098 program is like this; so are most programs designed as mail transport
1103 These programs give back a reliable positive acknowledgement and
1104 can be used with the mda option with no risk of mail loss. Unsafe
1105 MDAs, though, may return 0 even on delivery failure. If this
1106 happens, you will lose mail.
1108 The normal mode of \fIfetchmail\fR is to try to download only `new'
1109 messages, leaving untouched (and undeleted) messages you have already
1110 read directly on the server (or fetched with a previous \fIfetchmail
1111 --keep\fR). But you may find that messages you've already read on the
1112 server are being fetched (and deleted) even when you don't specify
1113 --all. There are several reasons this can happen.
1115 One could be that you're using POP2. The POP2 protocol includes no
1116 representation of `new' or `old' state in messages, so \fIfetchmail\fR
1117 must treat all messages as new all the time. But POP2 is obsolete, so
1120 A potential POP3 problem might be servers that insert messages
1121 in the middle of mailboxes (some VMS implementations of mail are
1122 rumored to do this). The \fIfetchmail\fR code assumes that new
1123 messages are appended to the end of the mailbox; when this is not true
1124 it may treat some old messages as new and vice versa. Using UIDL might
1125 fix this, otherwise, consider switching to IMAP.
1127 Yet another POP3 problem is that if they can't make tempfiles in the
1128 user's home directory, some POP3 servers will hand back an
1129 undocumented response that causes fetchmail to spuriously report "No
1132 The IMAP code uses the presence or absence of the server flag \eSeen
1133 to decide whether or not a message is new. This isn't the right thing
1134 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1135 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1136 the BSD-style Status flags set by mail user agents and set the \eSeen
1137 flag from them when appropriate. All Unix IMAP servers we know of do
1138 this, though it's not specified by the IMAP RFCs. If you ever trip over
1139 a server that doesn't, the symptom will be that messages you have
1140 already read on your host will look new to the server. In this
1141 (unlikely) case, only messages you fetched with \fIfetchmail --keep\fR
1142 will be both undeleted and marked old.
1144 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1145 instead, it asks the server's SMTP listener to start a queue flush
1146 to the client via SMTP. Therefore it sends only undelivered messages.
1149 Many SMTP listeners allow administrators to set up `spam filters' that
1150 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1151 triggers this feature will elicit an SMTP response which
1152 (unfortunately) varies according to the listener.
1156 return an error code of 571. This return value
1157 is blessed by RFC1893 as "Delivery not authorized, message refused".
1159 According to RFC2821, the correct thing to return in this situation is
1160 550 "Requested action not taken: mailbox unavailable" (the draft adds
1161 "[E.g., mailbox not found, no access, or command rejected for policy
1164 Older versions of the
1166 MTA return 501 "Syntax error in parameters or arguments".
1170 MTA runs 554 as an antispam response.
1173 may reject code with a 500 response (followed by an enhanced status
1174 code that contains more information).
1178 treats as antispam responses and discards
1179 the message can be set with the `antispam' option. This is one of the
1181 three circumstance under which fetchmail ever discards mail (the others
1182 are the 552 and 553 errors described below, and the suppression of
1183 multidropped messages with a message-ID already seen).
1187 is fetching from an IMAP server, the antispam response will be detected and
1188 the message rejected immediately after the headers have been fetched,
1189 without reading the message body. Thus, you won't pay for downloading
1190 spam message bodies.
1192 By default, the list of antispam responses is empty.
1194 If the \fIspambounce\fR option is on, mail that is spam-blocked
1195 triggers an RFC1892 bounce message informing the originator that we do
1196 not accept mail from it.
1198 .SH SMTP/ESMTP ERROR HANDLING
1199 Besides the spam-blocking described above, fetchmail takes special
1200 actions on the following SMTP/ESMTP error responses
1202 452 (insufficient system storage)
1203 Leave the message in the server mailbox for later retrieval.
1205 552 (message exceeds fixed maximum message size)
1206 Delete the message from the server. Send bounce-mail to the
1209 553 (invalid sending domain)
1210 Delete the message from the server. Don't even try to send
1211 bounce-mail to the originator.
1213 Other errors trigger bounce mail back to the originator.
1215 .SH THE RUN CONTROL FILE
1216 The preferred way to set up fetchmail is to write a
1217 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1218 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1219 When there is a conflict between the command-line arguments and the
1220 arguments in this file, the command-line arguments take precedence.
1222 To protect the security of your passwords,
1223 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1225 will complain and exit otherwise (this check is suppressed when
1228 You may read the \fI.fetchmailrc\fR file as a list of commands to
1231 is called with no arguments.
1232 .SS Run Control Syntax
1234 Comments begin with a '#' and extend through the end of the line.
1235 Otherwise the file consists of a series of server entries or global
1236 option statements in a free-format, token-oriented syntax.
1238 There are four kinds of tokens: grammar keywords, numbers
1239 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1240 A quoted string is bounded by double quotes and may contain
1241 whitespace (and quoted digits are treated as a string). An unquoted
1242 string is any whitespace-delimited token that is neither numeric, string
1243 quoted nor contains the special characters `,', `;', `:', or `='.
1245 Any amount of whitespace separates tokens in server entries, but is
1246 otherwise ignored. You may use standard C-style escapes (\en, \et,
1247 \eb, octal, and hex) to embed non-printable characters or string
1248 delimiters in strings.
1250 Each server entry consists of one of the keywords `poll' or `skip',
1251 followed by a server name, followed by server options, followed by any
1252 number of user descriptions. Note: the most common cause of syntax
1253 errors is mixing up user and server options.
1255 For backward compatibility, the word `server' is a synonym for `poll'.
1257 You can use the noise keywords `and', `with',
1258 \&`has', `wants', and `options' anywhere in an entry to make
1259 it resemble English. They're ignored, but but can make entries much
1260 easier to read at a glance. The punctuation characters ':', ';' and
1261 \&',' are also ignored.
1264 The `poll' verb tells fetchmail to query this host when it is run with
1265 no arguments. The `skip' verb tells
1267 not to poll this host unless it is explicitly named on the command
1268 line. (The `skip' verb allows you to experiment with test entries
1269 safely, or easily disable entries for hosts that are temporarily down.)
1271 .SS Keyword/Option Summary
1272 Here are the legal options. Keyword suffixes enclosed in
1273 square brackets are optional. Those corresponding to command-line
1274 options are followed by `-' and the appropriate option letter.
1275 If option is only relevant to a single mode of operation, it is noted
1276 as `s' or `m' for singledrop- or multidrop-mode, respectively.
1278 Here are the legal global options:
1282 Keyword Opt Mode Function
1285 Set a background poll interval in seconds
1287 set postmaster \& \& T{
1288 Give the name of the last-resort mail recipient
1290 set no bouncemail \& \& T{
1291 Direct error mail to postmaster rather than sender
1293 set no spambounce \& \& T{
1296 set logfile \& \& T{
1297 Name of a file to dump error and status messages to
1300 Name of the file to store UID lists in
1303 Do error logging through syslog(3).
1305 set no syslog \& \& T{
1306 Turn off error logging through syslog(3).
1308 set properties \& \& T{
1309 String value is ignored by fetchmail (may be used by extension scripts)
1313 Here are the legal server options:
1317 Keyword Opt Mode Function
1320 Specify DNS name of mailserver, overriding poll name
1323 Specify protocol (case insensitive):
1324 POP2, POP3, IMAP, APOP, KPOP
1326 local[domains] \& m T{
1327 Specify domain(s) to be regarded as local
1330 Specify TCP/IP service port
1332 auth[enticate] \& \& T{
1333 Set authentication type (default `any')
1336 Server inactivity timeout in seconds (default 300)
1339 Specify envelope-address header name
1342 Disable looking for envelope address
1345 Qmail virtual domain prefix to remove from user name
1348 Specify alternate DNS names of mailserver
1351 specify IP interface(s) that must be up for server poll to take place
1354 Specify IP address to monitor for activity
1357 Specify command through which to make server connections.
1360 Specify command through which to make listener connections.
1363 Enable DNS lookup for multidrop (default)
1366 Disable DNS lookup for multidrop
1369 Do comparison by IP address for multidrop
1371 no checkalias \& m T{
1372 Do comparison by name for multidrop (default)
1375 Force POP3 to use client-side UIDLs
1378 Turn off POP3 use of client-side UIDLs (default)
1381 Only check this site every N poll cycles; N is a numeric argument.
1384 Add poll tracing information to the Received header
1387 Pass in IPsec security option request.
1390 Set Kerberos principal (only useful with imap and kerberos)
1393 Set name for RFC2554 authentication to the ESMTP server.
1395 esmtppassword \& \& T{
1396 Set password for RFC2554 authentication to the ESMTP server.
1400 Here are the legal user options:
1404 Keyword Opt Mode Function
1407 Set remote user name
1408 (local user name if name followed by `here')
1411 Connect local and remote user names
1414 Connect local and remote user names
1417 Specify remote account password
1420 Connect to server over the specified base protocol using SSL encryption
1423 Specify file for client side public SSL certificate
1426 Specify file for client side private SSL key
1429 Force ssl protocol for connection
1432 Specify remote folder to query
1435 Specify smtp host(s) to forward to
1437 fetchdomains \& m T{
1438 Specify domains for which mail should be fetched
1440 smtpaddress -D \& T{
1441 Specify the domain to be put in RCPT TO lines
1444 Specify the user and domain to be put in RCPT TO lines
1447 Specify what SMTP returns are interpreted as spam-policy blocks
1450 Specify MDA for local delivery
1453 Specify BSMTP batch file to append to
1456 Command to be executed before each connection
1458 postconnect \& \& T{
1459 Command to be executed after each connection
1462 Don't delete seen messages from server
1465 Flush all seen messages before querying
1468 Fetch all messages whether seen or not
1471 Rewrite destination addresses for reply (default)
1474 Strip carriage returns from ends of lines
1477 Force carriage returns at ends of lines
1480 Force BODY=8BITMIME to ESMTP listener
1483 Strip Status and X-Mozilla-Status lines out of incoming mail
1485 dropdelivered \& \& T{
1486 Strip Delivered-To lines out of incoming mail
1489 Convert quoted-printable to 8-bit in MIME messages
1492 Idle waiting for new messages after each poll (IMAP only)
1495 Delete seen messages from server (default)
1498 Don't flush all seen messages before querying (default)
1500 no fetchall \& \& T{
1501 Retrieve only new messages (default)
1504 Don't rewrite headers
1507 Don't strip carriage returns (default)
1510 Don't force carriage returns at EOL (default)
1512 no pass8bits \& \& T{
1513 Don't force BODY=8BITMIME to ESMTP listener (default)
1515 no dropstatus \& \& T{
1516 Don't drop Status headers (default)
1518 no dropdelivered \& \& T{
1519 Don't drop Delivered-To headers (default)
1521 no mimedecode \& \& T{
1522 Don't convert quoted-printable to 8-bit in MIME messages (default)
1525 Don't idle waiting for new messages after each poll (IMAP only)
1528 Set message size limit
1531 Set message size warning interval
1534 Max # messages to forward in single connect
1537 Max # messages to fetch in single connect
1539 fetchsizelimit \& \& T{
1540 Max # message sizes to fetch in single transaction
1543 Use binary search for first unseen message (POP3 only)
1546 Perform an expunge on every #th message (IMAP and POP3 only)
1549 String value is ignored by fetchmail (may be used by extension scripts)
1553 Remember that all user options must \fIfollow\fR all server options.
1555 In the .fetchmailrc file, the `envelope' string argument may be
1556 preceded by a whitespace-separated number. This number, if specified,
1557 is the number of such headers to skip (that is, an argument of 1
1558 selects the second header of the given type). This is sometime useful
1559 for ignoring bogus Received headers created by an ISP's local delivery
1561 .SS Keywords Not Corresponding To Option Switches
1563 The `folder' and `smtphost' options (unlike their command-line
1564 equivalents) can take a space- or comma-separated list of names
1567 All options correspond to the obvious command-line arguments, except
1568 the following: `via', `interval', `aka', `is', `to', `dns'/`no dns',
1569 `checkalias'/`no checkalias', `password', `preconnect', `postconnect',
1570 `localdomains', `stripcr'/`no stripcr', `forcecr'/`no forcecr',
1571 `pass8bits'/`no pass8bits' `dropstatus/no dropstatus',
1572 `dropdelivered/no dropdelivered', `mimedecode/no mimedecode', `idle/no
1573 idle', and `no envelope'.
1575 The `via' option is for if you want to have more
1576 than one configuration pointing at the same site. If it is present,
1577 the string argument will be taken as the actual DNS name of the
1578 mailserver host to query.
1579 This will override the argument of poll, which can then simply be a
1580 distinct label for the configuration (e.g. what you would give on the
1581 command line to explicitly query this host).
1583 The `interval' option (which takes a numeric argument) allows you to poll a
1584 server less frequently than the basic poll interval. If you say
1585 \&`interval N' the server this option is attached to will only be
1586 queried every N poll intervals.
1588 The `is' or `to' keywords associate the following local (client)
1589 name(s) (or server-name to client-name mappings separated by =) with
1590 the mailserver user name in the entry. If an is/to list has `*' as
1591 its last name, unrecognized names are simply passed through.
1593 A single local name can be used to support redirecting your mail when
1594 your username on the client machine is different from your name on the
1595 mailserver. When there is only a single local name, mail is forwarded
1596 to that local username regardless of the message's Received, To, Cc,
1597 and Bcc headers. In this case
1599 never does DNS lookups.
1601 When there is more than one local name (or name mapping) the
1602 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1603 headers of retrieved mail (this is `multidrop mode'). It looks for
1604 addresses with hostname parts that match your poll name or your `via',
1605 `aka' or `localdomains' options, and usually also for hostname parts
1606 which DNS tells it are aliases of the mailserver. See the discussion
1607 of `dns', `checkalias', `localdomains', and `aka' for details on how
1608 matching addresses are handled.
1610 If \fIfetchmail\fR cannot match any mailserver usernames or
1611 localdomain addresses, the mail will be bounced.
1612 Normally it will be bounced to the sender, but if `nobounce' is on
1613 it will go to the postmaster (which in turn defaults to being the
1616 The `dns' option (normally on) controls the way addresses from
1617 multidrop mailboxes are checked. On, it enables logic to check each
1618 host address that doesn't match an `aka' or `localdomains' declaration
1619 by looking it up with DNS. When a mailserver username is recognized
1620 attached to a matching hostname part, its local mapping is added to
1621 the list of local recipients.
1623 The `checkalias' option (normally off) extends the lookups performed
1624 by the `dns' keyword in multidrop mode, providing a way to cope with
1625 remote MTAs that identify themselves using their canonical name, while
1626 they're polled using an alias.
1627 When such a server is polled, checks to extract the envelope address
1630 reverts to delivery using the To/Cc/Bcc headers (See below
1631 `Header vs. Envelope addresses').
1632 Specifying this option instructs
1634 to retrieve all the IP addresses associated with both the poll name
1635 and the name used by the remote MTA and to do a comparison of the IP
1636 addresses. This comes in handy in situations where the remote server
1637 undergoes frequent canonical name changes, that would otherwise
1638 require modifications to the rcfile. `checkalias' has no effect if
1639 `no dns' is specified in the rcfile.
1641 The `aka' option is for use with multidrop mailboxes. It allows you
1642 to pre-declare a list of DNS aliases for a server. This is an
1643 optimization hack that allows you to trade space for speed. When
1645 while processing a multidrop mailbox, grovels through message headers
1646 looking for names of the mailserver, pre-declaring common ones can
1647 save it from having to do DNS lookups. Note: the names you give
1648 as arguments to `aka' are matched as suffixes -- if you specify
1649 (say) `aka netaxs.com', this will match not just a hostname
1650 netaxs.com, but any hostname that ends with `.netaxs.com'; such as
1651 (say) pop3.netaxs.com and mail.netaxs.com.
1653 The `localdomains' option allows you to declare a list of domains
1654 which fetchmail should consider local. When fetchmail is parsing
1655 address lines in multidrop modes, and a trailing segment of a host
1656 name matches a declared local domain, that address is passed through
1657 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1660 If you are using `localdomains', you may also need to specify \&`no
1661 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1662 an envelope address from the Received line or X-Envelope-To header or
1663 whatever header has been previously set by `envelope'. If you set `no
1664 envelope' in the defaults entry it is possible to undo that in
1665 individual entries by using `envelope <string>'. As a special case,
1666 \&`envelope "Received"' restores the default parsing of
1669 The \fBpassword\fR option requires a string argument, which is the password
1670 to be used with the entry's server.
1672 The `preconnect' keyword allows you to specify a shell command to be
1673 executed just before each time
1675 establishes a mailserver connection. This may be useful if you are
1676 attempting to set up secure POP connections with the aid of
1678 If the command returns a nonzero status, the poll of that mailserver
1681 Similarly, the `postconnect' keyword similarly allows you to specify a
1682 shell command to be executed just after each time a mailserver
1683 connection is taken down.
1685 The `forcecr' option controls whether lines terminated by LF only are
1686 given CRLF termination before forwarding. Strictly speaking RFC821
1687 requires this, but few MTAs enforce the requirement it so this option
1688 is normally off (only one such MTA, qmail, is in significant use at
1691 The `stripcr' option controls whether carriage returns are stripped
1692 out of retrieved mail before it is forwarded. It is normally not
1693 necessary to set this, because it defaults to `on' (CR stripping
1694 enabled) when there is an MDA declared but `off' (CR stripping
1695 disabled) when forwarding is via SMTP. If `stripcr' and `forcecr' are
1696 both on, `stripcr' will override.
1698 The `pass8bits' option exists to cope with Microsoft mail programs that
1699 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1700 this option off (the default) and such a header present,
1702 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1703 messages actually using 8-bit ISO or KOI-8 character sets, which will
1704 be garbled by having the high bits of all characters stripped. If
1705 \&`pass8bits' is on,
1707 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1708 the listener is 8-bit-clean (as all the major ones now are) the right
1709 thing will probably result.
1711 The `dropstatus' option controls whether nonempty Status and
1712 X-Mozilla-Status lines are retained in fetched mail (the default) or
1713 discarded. Retaining them allows your MUA to see what messages (if
1714 any) were marked seen on the server. On the other hand, it can
1715 confuse some new-mail notifiers, which assume that anything with a
1716 Status line in it has been seen. (Note: the empty Status lines
1717 inserted by some buggy POP servers are unconditionally discarded.)
1719 The `dropdelivered' option controls whether Delivered-To headers will
1720 be kept in fetched mail (the default) or discarded. These headers are
1721 added by Qmail and Postfix mailservers in order to avoid mail loops but
1722 may get in your way if you try to "mirror" a mailserver within the same
1723 domain. Use with caution.
1725 The `mimedecode' option controls whether MIME messages using the
1726 quoted-printable encoding are automatically converted into pure 8-bit
1727 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1728 listener (that includes all of the major MTAs like sendmail), then
1729 this will automatically convert quoted-printable message headers and
1730 data into 8-bit data, making it easier to understand when reading
1731 mail. If your e-mail programs know how to deal with MIME messages,
1732 then this option is not needed. The mimedecode option is off by
1733 default, because doing RFC2047 conversion on headers throws away
1734 character-set information and can lead to bad results if the encoding
1735 of the headers differs from the body encoding.
1737 The `idle' option is intended to be used with IMAP servers supporting
1738 the RFC2177 IDLE command extension, but does not strictly require it.
1739 If it is enabled, and fetchmail detects that IDLE is supported, an
1740 IDLE will be issued at the end of each poll. This will tell the IMAP
1741 server to hold the connection open and notify the client when new mail
1742 is available. If IDLE is not supported, fetchmail will simulate it by
1743 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1744 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1745 sequences. On the other hand, an IDLE connection will eat almost all
1746 of your fetchmail's time, because it will never drop the connection
1747 and allow other pools to occur unless the server times out the IDLE.
1748 It also doesn't work with multiple folders; only the first folder will
1752 The `properties' option is an extension mechanism. It takes a string
1753 argument, which is ignored by fetchmail itself. The string argument may be
1754 used to store configuration information for scripts which require it.
1755 In particular, the output of `--configdump' option will make properties
1756 associated with a user entry readily available to a Python script.
1758 .SS Miscellaneous Run Control Options
1759 The words `here' and `there' have useful English-like
1760 significance. Normally `user eric is esr' would mean that
1761 mail for the remote user `eric' is to be delivered to `esr',
1762 but you can make this clearer by saying `user eric there is esr here',
1763 or reverse it by saying `user esr here is eric there'
1765 Legal protocol identifiers for use with the `protocol' keyword are:
1778 Legal authentication types are `any', `password', `kerberos', 'kerberos_v5'
1779 and `gssapi', `cram-md5', `otp', `ntlm', `ssh`.
1780 The `password' type specifies authentication by normal transmission of a
1781 password (the password may be plain text or subject to
1782 protocol-specific encryption as in APOP); `kerberos' tells
1783 \fIfetchmail\fR to try to get a Kerberos ticket at the start of each
1784 query instead, and send an arbitrary string as the password; and
1785 `gssapi' tells fetchmail to use GSSAPI authentication. See the description
1786 of the `auth' keyword for more.
1788 Specifying `kpop' sets POP3 protocol over port 1109 with Kerberos V4
1789 authentication. These defaults may be overridden by later options.
1791 There are currently four global option statements; `set logfile'
1792 followed by a string sets the same global specified by --logfile. A
1793 command-line --logfile option will override this. Also, `set daemon'
1794 sets the poll interval as --daemon does. This can be overridden by a
1795 command-line --daemon option; in particular --daemon 0 can be used to
1796 force foreground operation. The `set postmaster' statement sets the
1797 address to which multidrop mail defaults if there are no local
1798 matches. Finally, `set syslog' sends log messages to syslogd(8).
1800 .SH INTERACTION WITH RFC 822
1801 When trying to determine the originating address of a message,
1802 fetchmail looks through headers in the following order:
1806 Resent-Sender: (ignored if it doesn't contain an @ or !)
1807 Sender: (ignored if it doesn't contain an @ or !)
1814 The originating address is used for logging, and to set the MAIL FROM
1815 address when forwarding to SMTP. This order is intended to cope
1816 gracefully with receiving mailing list messages in multidrop mode. The
1817 intent is that if a local address doesn't exist, the bounce message
1818 won't be returned blindly to the author or to the list itself, but
1819 rather to the list manager (which is less annoying).
1821 In multidrop mode, destination headers are processed as follows:
1822 First, fetchmail looks for the Received: header (or whichever one is
1823 specified by the `envelope' option) to determine the local
1824 recipient address. If the mail is addressed to more than one recipient,
1825 the Received line won't contain any information regarding recipient addresses.
1827 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1828 lines. If they exists, they should contain the final recipients and
1829 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1830 lines doesn't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1831 looked for. (The presence of a Resent-To: is taken to imply that the
1832 person referred by the To: address has already received the original
1835 .SH CONFIGURATION EXAMPLES
1836 Note that although there are password declarations in a good many
1837 of the examples below, this is mainly for illustrative purposes.
1838 We recommend stashing account/password pairs in your $HOME/.netrc
1839 file, where they can be used not just by fetchmail but by ftp(1) and
1845 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1851 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
1854 Or, using some abbreviations:
1857 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
1860 Multiple servers may be listed:
1863 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
1864 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
1867 Here's a version of those two with more whitespace and some noise words:
1870 poll pop.provider.net proto pop3
1871 user "jsmith", with password secret1, is "jsmith" here;
1872 poll other.provider.net proto pop2:
1873 user "John.Smith", with password "My^Hat", is "John.Smith" here;
1876 This version is much easier to read and doesn't cost significantly
1877 more (parsing is done only once, at startup time).
1880 If you need to include whitespace in a parameter string, enclose the
1881 string in double quotes. Thus:
1884 poll mail.provider.net with proto pop3:
1885 user "jsmith" there has password "u can't krak this"
1886 is jws here and wants mda "/bin/mail"
1889 You may have an initial server description headed by the keyword
1890 `defaults' instead of `poll' followed by a name. Such a record
1891 is interpreted as defaults for all queries to use. It may be overwritten
1892 by individual server descriptions. So, you could write:
1897 poll pop.provider.net
1899 poll mail.provider.net
1900 user "jjsmith" there has password "secret2"
1903 It's possible to specify more than one user per server (this is only
1904 likely to be useful when running fetchmail in daemon mode as root).
1905 The `user' keyword leads off a user description, and every user specification
1906 in a multi-user entry must include it. Here's an example:
1909 poll pop.provider.net proto pop3 port 3111
1910 user "jsmith" with pass "secret1" is "smith" here
1911 user jones with pass "secret2" is "jjones" here keep
1914 This associates the local username `smith' with the pop.provider.net
1915 username `jsmith' and the local username `jjones' with the
1916 pop.provider.net username `jones'. Mail for `jones' is kept on the
1917 server after download.
1919 Here's what a simple retrieval configuration for a multi-drop mailbox
1923 poll pop.provider.net:
1924 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
1927 This says that the mailbox of account `maildrop' on the server is a
1928 multi-drop box, and that messages in it should be parsed for the
1929 server user names `golux', `hurkle', and `snark'. It further
1930 specifies that `golux' and `snark' have the same name on the
1931 client as on the server, but mail for server user `hurkle' should be
1932 delivered to client user `happy'.
1934 Here's an example of another kind of multidrop connection:
1937 poll pop.provider.net localdomains loonytoons.org toons.org:
1938 user maildrop with pass secret1 to * here
1941 This also says that the mailbox of account `maildrop' on the server is
1942 a multi-drop box. It tells fetchmail that any address in the
1943 loonytoons.org or toons.org domains (including sub-domain addresses like
1944 `joe@daffy.loonytoons.org') should be passed through to the local SMTP
1945 listener without modification. Be careful of mail loops if you do this!
1947 Here's an example configuration using ssh and the plugin option. The
1948 queries are made directly on the stdin and stdout of imapd via ssh.
1949 Note that in this setup, IMAP authentication can be skipped.
1952 poll mailhost.net with proto imap:
1953 plugin "ssh %h /usr/sbin/imapd" auth ssh;
1954 user esr is esr here
1957 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
1958 Use the multiple-local-recipients feature with caution -- it can bite.
1959 All multidrop features are ineffective in ETRN and ODMR modes.
1961 Also, note that in multidrop mode duplicate mails are suppressed. A
1962 piece of mail is considered duplicate if it has the same message-ID as
1963 the message immediately preceding and more than one addressee. Such
1964 runs of messages may be generated when copies of a message addressed
1965 to multiple users are delivered to a multidrop box.
1967 .SS Header vs. Envelope addresses
1968 The fundamental problem is that by having your mailserver toss several
1969 peoples' mail in a single maildrop box, you may have thrown away
1970 potentially vital information about who each piece of mail was
1971 actually addressed to (the `envelope address', as opposed to the
1972 header addresses in the RFC822 To/Cc/Bcc headers). This `envelope
1973 address' is the address you need in order to reroute mail properly.
1977 can deduce the envelope address. If the mailserver MTA is
1979 and the item of mail had just one recipient, the MTA will have written
1980 a `by/for' clause that gives the envelope addressee into its Received
1981 header. But this doesn't work reliably for other MTAs, nor if there is
1982 more than one recipient. By default, \fIfetchmail\fR looks for
1983 envelope addresses in these lines; you can restore this default with
1984 -E "Received" or \&`envelope Received'.
1986 Alternatively, some SMTP listeners and/or mail servers insert a header
1987 in each message containing a copy of the envelope addresses. This
1988 header (when it exists) is often `X-Envelope-To'. Fetchmail's
1989 assumption about this can be changed with the -E or `envelope' option.
1990 Note that writing an envelope header of this kind exposes the names of
1991 recipients (including blind-copy recipients) to all receivers of the
1992 messages; it is therefore regarded by some administrators as a
1993 security/privacy problem.
1995 A slight variation of the `X-Envelope-To' header is the `Delivered-To' put
1996 by qmail to avoid mail loops. It will probably prefix the user name with a
1997 string that normally matches the user's domain. To remove this prefix you
1998 can use the -Q or `qvirtual' option.
2000 Sometimes, unfortunately, neither of these methods works. When they
2001 all fail, fetchmail must fall back on the contents of To/Cc/Bcc
2002 headers to try to determine recipient addressees -- and these are not
2003 reliable. In particular, mailing-list software often ships mail with
2004 only the list broadcast address in the To header.
2008 cannot deduce a recipient address that is local, and the intended
2009 recipient address was anyone other than fetchmail's invoking user,
2010 mail will get lost. This is what makes the multidrop feature risky.
2012 A related problem is that when you blind-copy a mail message, the Bcc
2013 information is carried \fIonly\fR as envelope address (it's not put
2014 in the headers fetchmail can see unless there is an X-Envelope
2015 header). Thus, blind-copying to someone who gets mail over a
2016 fetchmail link will fail unless the the mailserver host routinely
2017 writes X-Envelope or an equivalent header into messages in your maildrop.
2019 .SS Good Ways To Use Multidrop Mailboxes
2020 Multiple local names can be used to administer a mailing list from the
2021 client side of a \fIfetchmail\fR collection. Suppose your name is
2022 \&`esr', and you want to both pick up your own mail and maintain a mailing
2023 list called (say) "fetchmail-friends", and you want to keep the alias
2024 list on your client machine.
2026 On your server, you can alias \&`fetchmail-friends' to `esr'; then, in
2027 your \fI.fetchmailrc\fR, declare \&`to esr fetchmail-friends here'.
2028 Then, when mail including `fetchmail-friends' as a local address
2029 gets fetched, the list name will be appended to the list of
2030 recipients your SMTP listener sees. Therefore it will undergo alias
2031 expansion locally. Be sure to include `esr' in the local alias
2032 expansion of fetchmail-friends, or you'll never see mail sent only to
2033 the list. Also be sure that your listener has the "me-too" option set
2034 (sendmail's -oXm command-line option or OXm declaration) so your name
2035 isn't removed from alias expansions in messages you send.
2037 This trick is not without its problems, however. You'll begin to see
2038 this when a message comes in that is addressed only to a mailing list
2039 you do \fInot\fR have declared as a local name. Each such message
2040 will feature an `X-Fetchmail-Warning' header which is generated
2041 because fetchmail cannot find a valid local name in the recipient
2042 addresses. Such messages default (as was described above) to being
2043 sent to the local user running
2045 but the program has no way to know that that's actually the right thing.
2047 .SS Bad Ways To Abuse Multidrop Mailboxes
2048 Multidrop mailboxes and
2050 serving multiple users in daemon mode do not mix. The problem, again, is
2051 mail from mailing lists, which typically does not have an individual
2052 recipient address on it. Unless
2054 can deduce an envelope address, such mail will only go to the account
2055 running fetchmail (probably root). Also, blind-copied users are very
2056 likely never to see their mail at all.
2058 If you're tempted to use
2060 to retrieve mail for multiple users from a single mail drop via POP or
2061 IMAP, think again (and reread the section on header and envelope
2062 addresses above). It would be smarter to just let the mail sit in the
2063 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2064 SMTP sends periodically (of course, this means you have to poll more
2065 frequently than the mailserver's expiry period). If you can't arrange
2066 this, try setting up a UUCP feed.
2068 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2069 your mailserver writes an envelope-address header that fetchmail can
2070 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2073 .SS Speeding Up Multidrop Checking
2074 Normally, when multiple users are declared
2076 extracts recipient addresses as described above and checks each host
2077 part with DNS to see if it's an alias of the mailserver. If so, the
2078 name mappings described in the to ... here declaration are done and
2079 the mail locally delivered.
2081 This is the safest but also slowest method. To speed it up,
2082 pre-declare mailserver aliases with `aka'; these are checked before
2083 DNS lookups are done. If you're certain your aka list contains
2085 DNS aliases of the mailserver (and all MX names pointing at it)
2086 you can declare `no dns' to suppress DNS lookups entirely and
2087 \fIonly\fR match against the aka list.
2090 To facilitate the use of
2092 in shell scripts, an exit code is returned to give an indication
2093 of what occurred during a given connection.
2095 The exit codes returned by
2099 One or more messages were successfully retrieved (or, if the -c option
2100 was selected, were found waiting but not retrieved).
2102 There was no mail awaiting retrieval. (There may have been old mail still
2103 on the server but not selected for retrieval.)
2105 An error was encountered when attempting to open a socket to retrieve
2106 mail. If you don't know what a socket is, don't worry about it --
2107 just treat this as an 'unrecoverable error'. This error can also be
2108 because a protocol fetchmail wants to use is not listed in /etc/services.
2110 The user authentication step failed. This usually means that a bad
2111 user-id, password, or APOP id was specified. Or it may mean that you
2112 tried to run fetchmail under circumstances where it did not have
2113 standard input attached to a terminal and could not prompt for a
2116 Some sort of fatal protocol error was detected.
2118 There was a syntax error in the arguments to
2121 The run control file had bad permissions.
2123 There was an error condition reported by the server. Can also
2126 timed out while waiting for the server.
2128 Client-side exclusion error. This means
2130 either found another copy of itself already running, or failed in such
2131 a way that it isn't sure whether another copy is running.
2133 The user authentication step failed because the server responded "lock
2134 busy". Try again after a brief pause! This error is not implemented
2135 for all protocols, nor for all servers. If not implemented for your
2136 server, "3" will be returned instead, see above. May be returned when
2137 talking to qpopper or other servers that can respond with "lock busy"
2138 or some similar text containing the word "lock".
2142 run failed while trying to do an SMTP port open or transaction.
2144 Fatal DNS error. Fetchmail encountered an error while performing
2145 a DNS lookup at startup and could not proceed.
2147 BSMTP batch file could not be opened.
2149 Poll terminated by a fetch limit (see the --fetchlimit option).
2151 Server busy indication.
2153 Server timed out during an IMAP IDLE.
2155 Internal error. You should see a message on standard error with
2160 queries more than one host, return status is 0 if \fIany\fR query
2161 successfully retrieved mail. Otherwise the returned error status is
2162 that of the last host queried.
2167 default run control file
2170 default location of file associating hosts with last message IDs seen
2171 (used only with newer RFC1725-compliant POP3 servers supporting the
2175 lock file to help prevent concurrent runs (non-root mode).
2178 your FTP run control file, which (if present) will be searched for
2179 passwords as a last resort before prompting for one interactively.
2181 /var/run/fetchmail.pid
2182 lock file to help prevent concurrent runs (root mode, Linux systems).
2185 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2188 If the FETCHMAILUSER variable is set, it is used as the name of the
2189 calling user (default local name) for purposes such as mailing error
2190 notifications. Otherwise, if either the LOGNAME or USER variable is
2191 correctly set (e.g. the corresponding UID matches the session user ID)
2192 then that name is used as the default local name. Otherwise
2193 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2194 session ID (this elaborate logic is designed to handle the case of
2195 multiple names per userid gracefully).
2197 If the environment variable FETCHMAILHOME is set to a valid and
2198 existing directory name, the .fetchmailrc and .fetchids and
2199 \&.fetchmail.pid files are put there instead of in the invoking user's
2200 home directory (and lose the leading dots on their names). The
2201 \&.netrc file is looked for in the the invoking user's home directory
2202 regardless of FETCHMAILHOME's setting.
2204 If the HOME_ETC variable is set, file $HOME_ETC/.fetchmailrc is used
2205 instead of ~/.fetchmailrc.
2210 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2211 forces a poll of all non-skipped servers (this is in accordance with
2212 the usual conventions for system daemons).
2216 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2217 so SIGHUP due to logout can retain the default action of killing it).
2221 in foreground while a background fetchmail is running will do
2222 whichever of these is appropriate to wake it up.
2224 .SH BUGS AND KNOWN PROBLEMS
2225 The mda and plugin options interact badly. In order to collect error
2226 status from the MDA, fetchmail has to change its normal signal
2227 handling so that dead plugin processes don't get reaped until the end
2228 of the poll cycle. This can cause resource starvation if too many
2229 zombies accumulate. So either don't deliver to a MDA using plugins or
2230 risk being overrun by an army of undead.
2232 The RFC822 address parser used in multidrop mode chokes on some
2233 @-addresses that are technically legal but bizarre. Strange uses of
2234 quoting and embedded comments are likely to confuse it.
2236 In a message with multiple envelope headers, only the last one
2237 processed will be visible to fetchmail. To get around this, use a
2238 mailserver-side filter that consolidates the contents of all envelope
2239 headers into a single one (procmail, mailagent, or maildrop can be
2240 programmed to do this fairly easily).
2242 Use of some of these protocols requires that the program send
2243 unencrypted passwords over the TCP/IP connection to the mailserver.
2244 This creates a risk that name/password pairs might be snaffled with a
2245 packet sniffer or more sophisticated monitoring software. Under Linux
2246 and FreeBSD, the --interface option can be used to restrict polling to
2247 availability of a specific interface device with a specific local or
2248 remote IP address, but snooping is still possible if (a) either host
2249 has a network device that can be opened in promiscuous mode, or (b)
2250 the intervening network link can be tapped. We recommend the use of
2252 tunnelling to not only shroud your passwords but encrypt the entire
2255 Use of the %F or %T escapes in an mda option could open a security
2256 hole, because they pass text manipulable by an attacker to a shell
2257 command. Potential shell characters are replaced by `_' before
2258 execution. The hole is further reduced by the fact that fetchmail
2259 temporarily discards any suid privileges it may have while running the
2260 MDA. For maximum safety, however, don't use an mda command containing
2261 %F or %T when fetchmail is run from the root account itself.
2263 Fetchmail's method of sending bouncemail and spam bounces requires that
2264 port 25 of localhost be available for sending mail via SMTP.
2268 while a background instance is running and break the syntax, the
2269 background instance will die silently. Unfortunately, it can't
2270 die noisily because we don't yet know whether syslog should be enabled.
2271 On some systems, fetchmail dies quietly even if there is no syntax
2272 error; this seems to have something to do with buggy terminal ioctl
2275 The -f - option (reading a configuration from stdin) is incompatible
2276 with the plugin option.
2278 The `principal' option only handles Kerberos IV, not V.
2280 Send comments, bug reports, gripes, and the like to the
2281 fetchmail-friends list <fetchmail-friends@lists.ccil.org>. An HTML FAQ is
2282 available at the fetchmail home page; surf to
2283 http://fetchmail.berlios.de/ or do a WWW search for pages with
2284 `fetchmail' in their titles.
2287 Eric S. Raymond <esr@snark.thyrsus.com>. Too many other people to
2288 name here have contributed code and patches.
2289 This program is descended from and replaces
2291 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2292 but some of its interface design is directly traceable to that
2295 This manual page has been improved by R.\ Hannes Beinert.
2297 Fetchmail is currently maintained by Matthias Andree and Rob Funk.
2300 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2301 .SH APPLICABLE STANDARDS
2304 RFC 821, RFC2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2308 RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.
2314 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC1734, RFC 1939, RFC 1957,
2318 RFC 1460, RFC 1725, RFC 1939.
2327 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
projects / ~andy / fetchmail / blob