+'\" t
+.\" ** The above line should force tbl to be used as a preprocessor **
+.\"
+.\" Man page for fetchmail
+.\"
.\" For license terms, see the file COPYING in this directory.
-.TH fetchmail 8
+.TH fetchmail 1
.SH NAME
-fetchmail \- fetch mail from a POP, IMAP, or ETRN-capable ESMTP server
+fetchmail \- fetch mail from a POP, IMAP, or ETRN-capable server
.SH SYNOPSIS
\fBfetchmail\fR [\fIoptions\fR] [\fImailserver...\fR]
program can gather mail from servers supporting any of the common
mail-retrieval protocols: POP2, POP3, IMAP2bis, and IMAP4. It can
also use the ESMTP ETRN extension. (The RFCs describing all these
-protocols are listed at the end of this ducument.)
+protocols are listed at the end of this document.)
.PP
While
.I fetchmail
As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
port 25 on the machine it is running on (localhost), just as though it
were being passed in over a normal TCP/IP link. The mail will then be
-delivered locally via your system's MTA (Mail Delivery Agent, usually
+delivered locally via your system's MDA (Mail Delivery Agent, usually
\fIsendmail\fR(8) but your system may use a different one such
as \fIsmail\fR, \fImmdf\fR, or \fIqmail\fR). All the delivery-control
mechanisms (such as \fI.forward\fR files) normally available through
-your system MTA and local delivery agents will therefore work.
+your system MDA and local delivery agents will therefore work.
.PP
The behavior of
.I fetchmail
without actually fetching or deleting mail (see EXIT CODES below).
This option turns off daemon mode (in which it would be useless). It
doesn't play well with queries to multiple sites, and doesn't work
-with ETRN. It's also prone to false positives if you leave read but
-undeleted mail in your server mailbox.
+with ETRN. It will return a false positive if you leave read but
+undeleted mail in your server mailbox and your fetch protocol can't
+tell kept messages from new ones. This means it will work with IMAP,
+not work with POP2, and may occasionally flake out under POP3.
.TP
.B \-s, --silent
Silent mode. Suppresses all progress/status messages that are normally
Verbose mode. All control messages passed between
.I fetchmail
and the mailserver are echoed to stderr. Overrides --silent.
+.SS Disposal Options
.TP
.B \-a, --all
(Keyword: fetchall)
option causes retrieved messages to remain in your folder on the
mailserver. This option does not work with ETRN.
.TP
-.B \-K, --kill
+.B \-K, --nokeep
+(Keyword: nokeep)
Delete retrieved messages from the remote mailserver. This
option forces retrieved mail to be deleted. It may be useful if
-you have specified a default of \fBnokill\fR in your
-\fI.fetchmailrc\fR. This option is forced on with ETRN.
+you have specified a default of \fBkeep\fR in your
+\&\fI.fetchmailrc\fR. This option is forced on with ETRN.
.TP
.B \-F, --flush
POP3/IMAP only. Delete old (previously retrieved) messages from the mailserver
before retrieving new messages. This option does not work with ETRN.
+Warning: if your local MTA hangs and fetchmail is aborted, the next
+time you run fetchmail, it will delete mail that was never delivered to you.
+What you probably want is the default setting: if you don't specify `-k', then
+fetchmail will automatically delete messages after successful delivery.
.SS Protocol and Query Options
.TP
.B \-p, \--protocol proto
.IP IMAP-K4
IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
with RFC 1731 Kerberos v4 authentication.
+.IP IMAP-GSS
+IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
+with RFC 1731 GSSAPI authentication.
.IP ETRN
Use the ESMTP ETRN option.
.RE
.B \-U, --uidl
(Keyword: uidl)
Force UIDL use (effective only with POP3). Force client-side tracking
-of `newness' of messages. Use with `keep' to use a mailbox as a baby
-news drop for a group of users; if the mailbox is periodically purged,
-every member will get a chance to read the message.
+of `newness' of messages (UIDL stands for ``unique ID listing'' and is
+described in RFC1725). Use with `keep' to use a mailbox as a baby
+news drop for a group of users.
.TP
.B \-P, --port
(Keyword: port)
while delivering mail through an MDA. Some possible MDAs are
"/usr/sbin/sendmail -oem", "/usr/lib/sendmail -oem",
"/usr/bin/formail", and "/usr/bin/deliver". Local delivery addresses
-will be inserted into the MDA command wherever you place a %s. Do
+will be inserted into the MDA command wherever you place a %T; the
+mail message's From address will be inserted where you place an %F. Do
\fInot\fR use an MDA invocation like
"sendmail -oem -t" that dispatches on the contents of To/Cc/Bcc, it
will create mail loops and bring the just wrath of many postmasters
poll. By default there is no limit. An explicit --fetchlimit of 0
overrides any limits set in your run control file.
This option does not work with ETRN.
+.TP
+.B -e, --expunge
+(keyword: expunge)
+When talking to an IMAP server,
+.I fetchmail
+normally issues an EXPUNGE command after each deletion in order to
+force the deletion to be done immediately. This is safest when your
+connection to the server is flaky and expensive, as it avoids
+resending duplicate mail after a line hit. However, on large
+mailboxes the overhead of re-indexing after every message can slam the
+server pretty hard, so if your connection is reliable it is good to do
+expunges less frequently. If you specify this option to an integer N,
+it tells
+.I fetchmail
+to only issue expunges on every Nth delete. An argument
+of zero suppresses expunges entirely (so no expunges at all will be
+done until the end of run).
+This option does not work with ETRN, POP2, or POP3.
.SS Authentication Options
.TP
.B \-u name, --username name
.I fetchmail
assumes will carry a copy of the mail's envelope address. Normally
this is `X-Envelope-To' but as this header is not standard, practice
-varies. See the discussion of multidrop address handling below. Note:
-do \fInot\fR say `envelope "Received"'; this is not necessary as fetchmail
-will try to parse Received lines if `envelope' is not specified (unless
-you explicitly disable Received parsing with `no envelope').
+varies. See the discussion of multidrop address handling below. As a
+special case, `envelope "Received"' enables parsing of sendmail-style
+Received lines. This is the default, and it should not be necessary
+unless you have globally disabled Received parsing with `no envelope'
+in the \fI.fetchmailrc\fR file.
+.TP
+.B -Q, --qvirtual
+(Keyword: qvirtual)
+The string assigned to this option will be removed from the user
+name found in the header specified with the \fIenvelope\fR option.
+This option is useful if you are using
+.I fetchmail
+to collect the mail for an entire domain and your ISP (or your mail
+redirection provider) is using qmail.
+One of the basic features of qmail is the
+.sp
+\&`Delivered-To:'
+.sp
+message header. Whenever qmail delivers a message to a local mailbox
+it puts the username and hostname of the envelope recipient on this
+line. The major reason for this is to prevent mail loops. To set up
+qmail to batch mail for a disconnected site the ISP-mailhost will have
+normally put that site in its `Virtualhosts' control file so it will
+add a prefix to all mail addresses for this site. This results in mail
+sent to 'username@userhost.userdom.dom.com' having a
+\&`Delivered-To:' line of the form:
+.sp
+Delivered-To: mbox-userstr-username@userhost.userdom.dom.com
+.sp
+The ISP can make the 'mbox-userstr-' prefix anything they choose
+but a string matching the user host name is likely.
+By using the option `envelope Delivered-To:' you can make fetchmail reliably
+identify the original envelope recipient, but you have to strip the
+`mbox-userstr-' prefix to deliver to the correct user.
+This is what this option is for.
.SH USER AUTHENTICATION
Every mode except ETRN requires authentication of the client.
option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
ticket from the mailserver at the start of each query.
.PP
-If you use IMAP-K4 the code will expect the IMAP server to have
-RFC1731-conformant AUTHENTICATE KERBEROS_V4 capability.
+If you use IMAP-K4, \fIfetchmail\fR will expect the IMAP server to have
+RFC1731-conformant AUTHENTICATE KERBEROS_V4 capability, and will use it.
+.PP
+If you use IMAP-GSS, \fIfetchmail\fR will expect the IMAP server to have
+RFC1731-conformant AUTHENTICATE GSSAPI capability, and will use it.
+Currently this has only been tested over Kerberos V, so you're expected
+to already have a ticket-granting ticket. You may pass a username different
+from your principal name using the standard \fB--user\fR command or by
+the \fI.fetchmailrc\fR option \fBuser\fR.
+.PP
+If you are using POP3, and the server issues a one-time-password
+challenge conforming to RFC1938, \fIfetchmail\fR will use your
+password as a pass phrase to generate the required response. This
+avoids sending secrets over the net unencrypted.
+.PP
+Compuserve's RPA authentication (similar to APOP) is supported. If
+you are using POP3, and the RPA code has been compiled into your
+binary, and you query a server in the Compuserve csi.com domain,
+\fIfetchmail\fR will try to perform an RPA pass-phrase authentication
+instead of sending over the password en clair.
.SH DAEMON MODE
The
It is possible to set a polling interval
in your
.I ~/.fetchmailrc
-file by saying `set demon <interval>', where <interval> is an
+file by saying `set daemon <interval>', where <interval> is an
integer number of seconds. If you do this, fetchmail will always
start in daemon mode unless you override it with the command-line
option --daemon 0 or -d0.
.PP
Only one daemon process is permitted per user; in daemon mode,
.I fetchmail
-makes a per-user lockfile to guarantee this. The option
+makes a per-user lockfile to guarantee this.
+.PP
+Normally, calling fetchmail with a daemon in the background sends a
+wakeup signal to the daemon, forcing it to poll mailservers
+immediately. (The wakeup signal is SIGHUP if fetchmail is running as
+root, SIGUSR1 otherwise.)
+.PP
+The option
.B --quit
-will kill a running daemon process. Otherwise, calling fetchmail with
-a daemon in the background sends a wakeup signal to the daemon,
-forcing it to poll mailservers immediately. (The wakeup signal is
-SIGHUP if fetchmail is running as root, SIGUSR1 otherwise.)
+will kill a running daemon process instead of waking it up (if there
+is no such option,
+.I fetchmail
+notifies you). If the --quit option is the only command-line option,
+that's all there is to it.
+.PP
+The quit option may also be mixed with other command-line options; its
+effect is to kill any running daemon before doing what the other
+options specify in combination with the rc file.
.PP
The
.B -t
or
.B --timeout
-option (keyword: timeout)allows you to set a server-nonresponse
+option (keyword: timeout) allows you to set a server-nonresponse
timeout in seconds. If a mailserver does not send a greeting message
or respond to commands for the given number of seconds,
\fIfetchmail\fR will hang up on it. Without such a timeout
\fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
down host. This would be particularly annoying for a \fIfetchmail\fR
-running in background.
+running in background. There is a default timeout which fetchmail -V
+will report.
.PP
The
.B -L
or
.B --logfile
option (keyword: set logfile) allows you to redirect status messages
-emitted while in daemon mode into a specified logfile (follow the
+emitted while detached into a specified logfile (follow the
option with the logfile name). The logfile is opened for append, so
previous messages aren't deleted. This is primarily useful for
debugging configurations.
option was used.
.PP
The
+.B --invisible
+option tries to make fetchmail invisible. Normally, fetchmail behaves
+like any other MTA would -- it generates a Received header into each
+message describing its place in the chain of transmission, and tells
+the MTA it forwards to that the mail came from the machine fetchmail
+itself is running on. If the invisible option is on, the Received
+header is suppressed and fetchmail tries to spoof the MTA it forwards
+to into thinking it came directly from the mailserver host.
+.PP
+The
.B \-N
-or --nodetach option suppresses detachment of the daemon process
-from its control terminal. This is primarily useful for debugging.
+or --nodetach option suppresses backgrounding and detachment of the
+daemon process from its control terminal. This is primarily useful
+for debugging. Note that this also causes the logfile option to be
+ignored (though perhaps it shouldn't).
.PP
Note that while running in daemon mode polling a POP2 or POP3 server,
transient errors (such as DNS failures or sendmail delivery refusals)
spam message bodies.
.SH THE RUN CONTROL FILE
-The preferred way to set up fetchmail (and the only way if you want to
-avoid specifying passwords each time it runs) is to write a
+The preferred way to set up fetchmail is to write a
\&\fI.fetchmailrc\fR file in your home directory. When there is a
conflict between the command-line arguments and the arguments in this
file, the command-line arguments take precedence.
be executed when
.I fetchmail
is called with no arguments.
+.SS Run Control Syntax
.PP
Comments begin with a '#' and extend through the end of the line.
Otherwise the file consists of a series of server entries or global
.PP
Each server entry consists of one of the keywords `poll' or `skip',
followed by a server name, followed by server options, followed by any
-number of user descriptions.
+number of user descriptions. Note: the most common cause of syntax
+errors is mixing up user and server options.
+.PP
+For backward compatibility, the word `server' is a synonym for `poll'.
+.PP
+You can use the noise keywords `and', `with',
+\&`has', `wants', and `options' anywhere in an entry to make
+it resemble English. They're ignored, but but can make entries much
+easier to read at a glance. The punctuation characters ':', ';' and
+\&',' are also ignored.
.PP
+.SS Poll vs. Skip
The `poll' verb tells fetchmail to query this host when it is run with
no arguments. The `skip' verb tells
.I fetchmail
line. (The `skip' verb allows you to experiment with test entries
safely, or easily disable entries for hosts that are temporarily down.)
.PP
-Legal server options are:
+.SS Keyword/Option Summary
+Here are the legal server options. Keyword suffixes enclosed in
+square brackets are optional. Those corresponding to command-line
+options are followed by `-' and the appropriate option letter.
- protocol (or proto)
- port
- authenticate (or auth)
- timeout
- envelope
- aka
- interface
- monitor
- dns
- no dns
+.TS
+l l lw34.
+Keyword Opt Function
+_
+via \& T{
+Specify DNS name of mailserver, overriding poll name
+T}
+proto[col] -p T{
+Specify protocol (case insensitive):
+POP2, POP3, IMAP, IMAP-K4, IMAP-GSS, APOP, KPOP
+T}
+port -P T{
+Specify TCP/IP service port
+T}
+auth[enticate] -A T{
+Set preauthentication type (default `password')
+T}
+timeout -t T{
+Server inactivity timout in seconds (default 300)
+T}
+envelope -E T{
+Specify envelope-address header name
+T}
+no envelope \& T{
+Disable looking for envelope address
+T}
+qvirtual -Q T{
+Qmail virtual domain prefix to remove from user name
+T}
+aka \& T{
+Specify alternate DNS names of mailserver
+T}
+interface -I T{
+specify IP interface(s) that must be up for server poll to take place
+T}
+monitor -M T{
+Specify IP address to monitor for activity
+T}
+dns \& T{
+Enable DNS lookup for multidrop (default)
+T}
+no dns \& T{
+Disable DNS lookup for multidrop
+T}
+uidl -U T{
+Force POP3 to use client-side UIDLs
+T}
+no uidl \& T{
+Turn off POP3 use of client-side UIDLs (default)
+T}
+.TE
-Legal user options are
+Here are the legal user options:
- username (or user)
- is
- to
- password (or pass)
- folder
- smtphost (or smtp)
- mda
- preconnect
- keep
- flush
- fetchall
- rewrite
- stripcr
- forcecr
- pass8bits
- dns
- no keep
- no flush
- no fetchall
- no rewrite
- no stripcr
- no forcecr
- no pass8bits
- no dns
- no envelope
- limit
- batchlimit
- fetchlimit
- syslog
-.PP
-The 'folder' and 'smtphost' options can take a space- or
-comma-separated list of names following them.
+.TS
+l l lw34.
+Keyword Opt Function
+_
+user[name] -u T{
+Set remote user name
+(local user name if name followed by `here')
+T}
+is \& T{
+Connect local and remote user names
+T}
+to \& T{
+Connect local and remote user names
+T}
+pass[word] \& T{
+Specify remote account password
+T}
+folder -r T{
+Specify remote folder to query
+T}
+smtphost -S T{
+Specify smtp host(s) to forward to
+T}
+mda -m T{
+Specify MDA for local delivery
+T}
+preconnect \& T{
+Command to be executed before each connection
+T}
+postconnect \& T{
+Command to be executed after each connection
+T}
+keep -k T{
+Don't delete seen messages from server
+T}
+flush -F T{
+Flush all seen messages before querying
+T}
+fetchall -a T{
+Fetch all messages whether seen or not
+T}
+rewrite \& T{
+Rewrite destination addresses for reply (default)
+T}
+stripcr \& T{
+Strip carriage returns from ends of lines
+T}
+forcecr \& T{
+Force carriage returns at ends of lines
+T}
+pass8bits \& T{
+Force BODY=8BITMIME to ESMTP listener
+T}
+dropstatus \& T{
+Strip Status lines out of incoming mail
+T}
+no keep -K T{
+Delete seen messages from server (default)
+T}
+no flush \& T{
+Don't flush all seen messages before querying (default)
+T}
+no fetchall \& T{
+Retrieve only new messages (default)
+T}
+no rewrite \& T{
+Don't rewrite headers
+T}
+no stripcr \& T{
+Don't strip carriage returns (default)
+T}
+no forcecr \& T{
+Don't force carriage returns at EOL (default)
+T}
+no pass8bits \& T{
+Don't force BODY=8BITMIME to ESMTP listener (default)
+T}
+no dropstatus \& T{
+Don't drop Status headers (default)
+T}
+limit -l T{
+Set message size limit
+T}
+batchlimit -b T{
+Max # messages to fetch in single connect
+T}
+fetchlimit -B T{
+Max # messages to forward in single connect
+T}
+expunge -e T{
+Perform an expunge on every #th message (IMAP only)
+T}
+syslog \& T{
+Do error logging through syslog(3).
+T}
+.TE
+.PP
+Remember that all user options must \fIfollow\fR all server options.
+.PP
+In the .fetchmailrc file, the `envelope' string argument may be
+preceded by a whitespace-separated number. This number, if specified,
+is the number of such headers to skip (that is, an argument of 1
+selects the second header of the given type). This is sometime useful
+for ignoring bogus Received headers created by an ISP's local delivery
+agent.
+.SS Keywords Not Corresponding To Option Switches
+.PP
+The `folder' and `smtphost' options (unlike their command-line
+equivalents) can take a space- or comma-separated list of names
+following them.
.PP
All options correspond to the obvious command-line arguments, except
-the following: `interval', `aka', `is', `to', `dns'/`no dns', `password',
-\&`preconnect', `localdomains', `stripcr'/`no stripcr' ,
-\&`forcecr'/`no forcecr', `pass8bits'/`no pass8bits' and `no received'.
+the following: `via', `interval', `aka', `is', `to', `dns'/`no dns',
+\&`password', \&`preconnect', \&`postconnect', `localdomains',
+\&`stripcr'/`no stripcr', \&`forcecr'/`no forcecr', `pass8bits'/`no
+pass8bits' `dropstatus/no dropstatus', and `no envelope'.
+.PP
+The `via' option is for use with ssh, or if you want to have more
+than one configuration pointing at the same site. If it is present,
+the string argument will be taken as the actual DNS name of the
+mailserver host to query.
+This will override the argument of poll, which can then simply be a
+distinct label for the configuration (e.g. what you would give on the
+command line to explicitly query this host).
+If the `via' name is `localhost', the poll name will also still be
+used as a possible match in multidrop mode; otherwise the `via' name
+will be used instead and the poll name will be purely a label.
.PP
The `interval' option (which takes a numeric argument) allows you to poll a
server less frequently than the basic poll interval. If you say
When there is more than one local name (or name mapping) the
\fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
headers of retrieved mail (this is `multidrop mode'). It looks for
-addresses with hostname parts that match your `aka' or `localdomains'
-options, and usually also for hostname parts which DNS tells it are
-aliases of the mailserver. See the discussion of `dns',
-`localdomains', and `aka' for details on how matching addresses are
-handled. If \fIfetchmail\fR cannot match any mailserver usernames or
-localdomain addresses, the default recipient is the calling user.
+addresses with hostname parts that match your poll name or your `via',
+`aka' or `localdomains' options, and usually also for hostname parts
+which DNS tells it are aliases of the mailserver. See the discussion
+of `dns', `localdomains', and `aka' for details on how matching
+addresses are handled. If \fIfetchmail\fR cannot match any mailserver
+usernames or localdomain addresses, the default recipient is the
+calling user (as set by the USER or LOGNAME variable in the
+environment; you could use this to redirect to an alias like postmaster).
.PP
The `dns' option (normally on) controls the way addresses from
multidrop mailboxes are checked. On, it enables logic to check each
an envelope address from the Received line or X-Envelope-To header or
whatever header has been previously set by `envelope'. If you set `no
envelope' in the defaults entry it is possible to undo that in
-individual entries by using `envelope <string>'.
+individual entries by using `envelope <string>'. As a special case,
+\&`envelope "Received"' restores the default parsing of
+Received lines.
.PP
The \fBpassword\fR option requires a string argument, which is the password
to be used with the entry's server.
establishes a mailserver connection. This may be useful if you are
attempting to set up secure POP connections with the aid of
.IR ssh (1).
+If the command returns a nonzero status, the poll of that mailserver
+will be aborted.
+.PP
+Similarly, the `postconnect' keyword similarly allows you to specify a
+shell command to be executed just after each time a mailserver
+connection is taken down.
.PP
The `forcecr' option controls whether lines terminated by LF only are
given CRLF termination before forwarding. Strictly speaking RFC821
the listener is 8-bit-clean (as all the major ones now are) the right
thing will probably result.
.PP
-Legal protocol identifiers are
+The `dropstatus' option controls whether nonempty Status lines are
+retained in fetched mail (the default) or discarded. Retaining them
+allows your MUA to see what messages (if any) were marked seen on the
+client. On the other hand, it can confuse some new-mail notifiers,
+which assume that anything with a Status line in it has been seen.
+(Note: the empty Status lines inserted by some buggy POP servers are
+unconditionally discarded.)
+.PP
+.SS Miscellaneous Run Control Options
+The words `here' and `there' have useful English-like
+significance. Normally `user eric is esr' would mean that
+mail for the remote user `eric' is to be delivered to `esr',
+but you can make this clearer by saying `user eric there is esr here',
+or reverse it by saying `user esr here is eric there'
+.PP
+Legal protocol identifiers for use with the `protocol' keyword are:
auto (or AUTO)
pop2 (or POP2)
pop3 (or POP3)
imap (or IMAP)
imap-k4 (or IMAP-K4)
+ imap-gss (or IMAP-GSS)
apop (or APOP)
kpop (or KPOP)
Specifying `kpop' sets POP3 protocol over port 1109 with Kerberos V4
preauthentication. These defaults may be overridden by later options.
.PP
-You can use the noise keywords `and', `with',
-\&`has', `wants', and `options' anywhere in an entry to make
-it resemble English. They're ignored, but but can make entries much
-easier to read at a glance. The punctuation characters ':', ';' and
-\&',' are also ignored.
-.PP
-The words `here' and `there' have useful English-like
-significance. Normally `user eric is esr' would mean that
-mail for the remote user `eric' is to be delivered to `esr',
-but you can make this clearer by saying `user eric there is esr here',
-or reverse it by saying `user esr here is eric there'
-.PP
-For backward compatibility, the word `server' is a synonym for `poll'.
-.PP
-There are currently three global option statements; `set logfile = '
+There are currently three global option statements; `set logfile'
followed by a string sets the same global specified by --logfile. A
command-line --logfile option will override this. Also, `set daemon'
sets the poll interval as --daemon does. This can be overridden by
a command-line --daemon option; in particular --daemon 0 can be used
to force foreground operation. Finally, `set syslog' sends log
messages to syslogd(8).
-.PP
+
+.SH CONFIGURATION EXAMPLES
Basic format is:
.nf
loonytoons.org domain (including subdomain addresses like
`joe@daffy.loonytoons.org') should be passed through to the local SMTP
listener without modification. Be careful of mail loops if you do this!
+.PP
+Here's an example configuration using ssh. The queries go through an
+ssh connecting local port 1234 to port 110 on mailhost.net; the
+preconnect command sets up the ssh.
+
+.nf
+poll mailhost.net via localhost port 1234 with pop3:
+ preconnect "ssh -f -L 1234:mailhost.net:110
+ mailhost.net sleep 20 </dev/null >/dev/null";
+.fi
.SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
Use the multiple-local-recipients feature with caution -- it can bite.
.SS Header vs. Envelope addresses
The fundamental problem is that by having your mailserver toss several
-peoples' mail in a box, you may have thrown away potentially vital
-information about who each piece of mail was actually addressed to
-(the `envelope address', as opposed to the header addresses in the RFC822
-To/Cc/Bcc headers). This `envelope address' is the address you need
-in order to reroute mail properly.
+peoples' mail in a single maildrop box, you may have thrown away
+potentially vital information about who each piece of mail was
+actually addressed to (the `envelope address', as opposed to the
+header addresses in the RFC822 To/Cc/Bcc headers). This `envelope
+address' is the address you need in order to reroute mail properly.
.PP
Sometimes
.I fetchmail
can deduce the envelope address. If the mailserver MTA is
.I sendmail
and the item of mail had just one recipient, the MTA will have written
-a `for' clause that gives the envelope addressee into its Received
-header. But this doesn't work reliably for other MTAs, nor if there is more
-than one recipient.
+a `by/for' clause that gives the envelope addressee into its Received
+header. But this doesn't work reliably for other MTAs, nor if there is
+more than one recipient. By default, \fIfetchmail\fR looks for
+envelope addresses in these lines; you can restore this default with
+-E "Received" or \&`envelope Received'.
.PP
Alternatively, some SMTP listeners and/or mail servers insert a header
in each message containing a copy of the envelope addresses. This
header (when it exists) is often `X-Envelope-To'. Fetchmail's
assumption about this can be changed with the -E or `envelope' option.
-Note that writing an envelope header of this kind exposes the names
-of recipients to all receivers of the messages; it is therefore
-regarded by some administrators as a security/privacy problem.
+Note that writing an envelope header of this kind exposes the names of
+recipients (including blind-copy recopients) to all receivers of the
+messages; it is therefore regarded by some administrators as a
+security/privacy problem.
+.PP
+A slight variation of the `X-Envelope-To' header is the `Delivered-To' put
+by qmail to avoid mail loops. It will probably prefix the user name with a
+string that normally matches the user's domain. To remove this prefix you
+can use the -Q or `qvirtual' option.
.PP
Sometimes, unfortunately, neither of these methods works. When they
-both fail, fetchmail must fall back on the contents of To/Cc/Bcc
+all fail, fetchmail must fall back on the contents of To/Cc/Bcc
headers to try to determine recipient addressees -- and these are not
reliable. In particular, mailing-list software often ships mail with
only the list broadcast address in the To header.
cannot deduce a recipient address that is local, and the intended
recipient address was anyone other than fetchmail's invoking user,
mail will get lost. This is what makes the multidrop feature risky.
+.PP
+A related problem is that when you blind-copy a mail message, the Bcc
+information is carried \fIonly\fR as envelope address (it's not put
+in the headers fetchmail can see unless there is an X-Envelope
+header). Thus, blind-copying to someone who gets mail over a
+fetchmail link will fail unless the the mailserver host routinely
+writes X-Envelope or an equivalent header into messages in your maildrop.
.SS Good Ways To Use Multidrop Mailboxes
Multiple local names can be used to administer a mailing list from the
recipient address on it. Unless
.I fetchmail
can deduce an envelope address, such mail will only go to the account
-running fetchmail (probably root).
+running fetchmail (probably root). Also, blind-copied users are very
+likely never to see their mail at all.
.PP
If you're tempted to use
.I fetchmail
-to retrieve mail for multiple users via POP or IMAP, think again.
-It would be smarter to just let it sit in the mailserver's queue and
-use ETRN mode to trigger SMTP sends periodically (of course, this
-means you have to poll more frequently than the mailserver's expiry
-period). If you can't arrange this, try setting up a UUCP feed.
+to retrieve mail for multiple users from a single mail drop via POP or
+IMAP, think again (and reread the section on header and envelope
+addresses above). It would be smarter to just let the mail sit in the
+mailserver's queue and use fetchmail's ETRN mode to trigger SMTP sends
+periodically (of course, this means you have to poll more frequently
+than the mailserver's expiry period). If you can't arrange this, try
+setting up a UUCP feed.
+.PP
+If you absolutely \fImust\fR use multidrop for this purpose, make sure
+your mailserver writes an envelope-address header that fetchmail can
+see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
+to haunt you.
.SS Speeding Up Multidrop Checking
Normally, when multiple user are declared
.I fetchmail.
run failed while trying to do an SMTP port open or transaction.
.IP 11
+Fatal DNS error. Fetchmail encountered an error while performing
+a DNS lookup at startup and could not proceed.
+.IP 11
Internal error. You should see a message on standard error with
details.
.PP
When
.I fetchmail
-queries more than one host, the returned status is that of the last
-host queried.
+queries more than one host, return status is 0 if \fIany\fR query
+successfully retrieved mail. Otherwise the returned error status is
+that of the last host queried.
.SH AUTHOR
Eric S. Raymond <esr@snark.thyrsus.com>.
lock file to help prevent concurrent runs (non-root mode).
.TP 5
/var/run/fetchmail.pid
-lock file to help prevent concurrent runs (root mode).
+lock file to help prevent concurrent runs (root mode, Linux systems).
+.TP 5
+/etc/fetchmail.pid
+lock file to help prevent concurrent runs (root mode, systems without /var/run).
.SH ENVIRONMENT
For correct initialization,
are technically legal but bizarre. Strange uses of quoting and
embedded comments are likely to confuse it.
.PP
-Use of any of the supported protocols other than APOP, KPOP, IMAP-K4,
-or ETRN requires that the program send unencrypted passwords over the
-TCP/IP connection to the mailserver. This creates a risk that
-name/password pairs might be snaffled with a packet sniffer or more
-sophisticated monitoring software. Under Linux, the --interface
-option can be used to restrict polling to availability of a specific
-interface device with a specific local IP address, but snooping is
-still possible if (a) either host has a network device that can be
-opened in promiscuous mode, or (b) the intervening network link can be
-tapped.
+Use of any of the supported protocols other than POP3 with OTP or RPA, APOP,
+KPOP, IMAP-K4, IMAP-GSS, or ETRN requires that the program send unencrypted
+passwords over the TCP/IP connection to the mailserver. This creates
+a risk that name/password pairs might be snaffled with a packet
+sniffer or more sophisticated monitoring software. Under Linux, the
+--interface option can be used to restrict polling to availability of
+a specific interface device with a specific local IP address, but
+snooping is still possible if (a) either host has a network device
+that can be opened in promiscuous mode, or (b) the intervening network
+link can be tapped.
.PP
Send comments, bug reports, gripes, and the like to Eric S. Raymond
<esr@thyrsus.com>. An HTML FAQ is available at the fetchmail home
.TP 5
ETRN:
RFC 1985
+.TP 5
+OTP:
+RFC 1938
projects / ~andy / fetchmail / blobdiff