path: root/mail/exim/files/exim.8

.TH EXIM 8
.SH exim
exim \- Mail Transfer Agent
.SH SYNOPSIS
.B exim
.I "[options] arguments ..."
.br
.B mailq
.I "[options] arguments ..."
.br
.B rmail
.I "[options] arguments ..."
.br
.B rsmtp
.I "[options] arguments ..."
.br
.B runq
.I "[options] arguments ..."
.br
.B sendmail
.I "[options] arguments ..."
.SH "DESCRIPTION"
.B Exim
is a mail transport agent (MTA) developed at the University of
Cambridge for use on Unix systems connected to the Internet. It is
freely available under the terms of the GNU General Public Licence. In
style it is similar to Smail 3, but its facilities are more extensive,
and in particular it has some defences against mail bombs and
unsolicited junk mail, in the form of options for refusing messages
from particular hosts, networks, or senders.
.PP
Exim's command line takes the standard Unix form of a sequence of
options, each starting with a hyphen character, followed by a number
of arguments.  The options are compatible with the main options of
Sendmail, and there are also some additional options, some of which
are compatible with Smail 3.  Certain combinations of options do not
make sense, and provoke an error if used. The form of the arguments
depends on which options are set.
.PP
If Exim is called under the name mailq, it behaves as if the option
-bp were present before any other options. This is for compatibility
with some systems that contain a command of that name in one of the
standard libraries, symbolically linked to /usr/lib/sendmail.
.PP
If Exim is called under the name rsmtp it behaves as if the option -bS
were present before any other options, for compatibility with
smail. The -bS option is used for reading in a number of messages in
batched SMTP format.
.PP
If Exim is called under the name rmail it behaves as if the option -i
were present before any other options, for compatibility with
smail. The -i option is used for reading a message that should not be
terminated by a dot on a line by itself. The name rmail is used as an
interface by some UUCP systems.
.PP
If Exim is called under the name runq it behaves as if the option -q
were present before any other options, for compatibility with
smail. The -q option causes a single queue-runner process to be
started.
.SH LIMITATIONS
For the benefit of those reading this overview to see whether Exim is
of interest to them, its limitations are listed first.
.TP
.B ANSI-C
Exim is written in ANSI C. This should not be much of a limitation
these days. However, to help with systems that lack a true ANSI C
library, Exim avoids making any use of the value returned by the
sprintf() function, which is one of the main incompatibilities. It has
its own version of strerror() for use with SunOS4 and any other system
that lacks this function, and a macro can be defined to turn memmove()
into bcopy() if necessary.
.TP
.B Filenames
Exim uses file names that are longer than 14 characters.
.TP
.B Bangpaths
Exim is intended for use as an Internet mailer, and therefore handles
addresses in RFC 822 domain format only. It cannot handle 'bang
paths', though simple two-component bang paths can be converted by a
straightforward rewriting configuration.
.TP
.B Domains required
Exim insists that every address it handles has a domain attached. For
incoming local messages, domainless addresses are automatically
qualified with a configured domain value. Configuration options
specify from which remote systems unqualified addresses are
acceptable.
.TP
.B Transports
The only external transport currently implemented is an SMTP transport
over a TCP/IP network (using sockets), suitable for machines on the
Internet. However, a pipe transport is available, and there are
facilities for writing messages to files in 'batched SMTP' format;
this can be used to send messages to some other transport
mechanism. Batched SMTP input is also catered for.
.SH FEATURES
Exim follows the same general approach of decentralized control that
Smail 3 does. There is no central process doing overall management of
mail delivery.  However, unlike Smail, the independent delivery
processes share data in the form of 'hints', which makes delivery more
efficient in some cases. The hints are kept in a number of DBM
files. If any of these files are lost, the only effect is to change
the pattern of delivery attempts and retries.
.PP
Many configuration options can be given as expansion strings, and as
these can include file lookups, much of Exim's operation can be made
table-driven if desired. For example, it is possible to do local
delivery on a machine on which the users do not have accounts.
.PP
Regular expressions are available in a number of configuration
parameters.
.PP
Domain lists can include file lookups, making it possible to support a
large number of local domains.
.PP
Exim has flexible retry algorithms, applicable to mail routing as well as
to delivery.
.PP
Exim contains header and envelope rewriting facilities.
.PP
Unqualified addresses are accepted only from specified hosts or networks.
.PP
Exim can perform multiple deliveries down the same SMTP channel after
deliveries to a host have been delayed.
.PP
Exim can be configured to do local deliveries immediately but to leave
remote deliveries until the message is picked up by a queue-runner
process. This increases the likelihood of multiple messages being sent
down a single SMTP connection.
.PP
When copies of a message have to be delivered to more than one remote
host, up to a configured maximum number of remote deliveries can be
done in parallel.
.PP
Exim supports optional checking of incoming return path (sender) and
receiver addresses as they are received by SMTP.
.PP
SMTP calls from specific machines, optionally from specific idents,
can be locked out, and incoming SMTP messages from specific senders
can also be locked out.
.PP
It is possible to control which hosts may use the Exim host as a relay
for onward transmission of mail; the control can be made to depend on
the address domain.
.PP
Messages on the queue can be 'frozen' and 'thawed' by the
administrator.
.PP
The maximum size of message can be specified.  Exim can handle a
number of independent local domains on the same machine; each domain
can have its own alias files, etc. These are commonly called "virtual
domains".
.PP
Exim stats a user's home directory before looking for a .forward file,
in order to detect the case of a missing NFS mount.
.PP
Exim contains an optional built-in mail filtering facility. This
enables users to set up their own mail filtering in a straightfoward
manner without the need to run an external program. There can also be
a system filter file that applies to all messages.
.PP
There is support for multiple user mailboxes controlled by prefixes or
suffixes on the user name, either via the filter mechanism or through
multiple .forward files.
.PP
Periodic warnings are automatically sent to messages' senders when
delivery is delayed - the time between warnings is configurable.
.PP
A queue run can be manually started to deliver just a particular
portion of the queue, or those messages with a recipient whose address
contains a given string.
.PP
Exim can be configured to run as root all the time, except when
performing local deliveries, which it always does in a separate
process under an appropriate uid and gid. Alternatively, it can be
configured to run as root only when needed; in particular, it need not
run as root when receiving incoming messages or when sending out
messages over SMTP.
.PP
I have tried to make the wording of delivery failure messages clearer
and simpler, for the benefit of those less-experienced people who are
now using email.
.PP
The Exim Monitor is an optional extra; it displays information about
Exim's processing in an X window, and an administrator can perform a
number of control actions from the window interface.
.SH METHOD OF OPERATION
When Exim receives a message, it writes two files in its spool
directory.  The first contains the envelope information, the current
status of the message, and the headers, while the second contains the
body of the message. The status of the message includes a complete
list of recipients and a list of those that have already received the
message. The header file gets updated during the course of delivery if
necessary.
.PP
A message remains in the spool directory until it is completely
delivered to its recipients or to an error address, or until it is
deleted by an administrator or by the user who originally created
it. In cases when delivery cannot proceed - for example, when a
message can neither be delivered to its recipients nor returned to its
sender, the message is marked 'frozen' on the spool, and no more
deliveries are attempted. The administrator can thaw such messages
when the problem has been corrected, and can also freeze individual
messages by hand if necessary.
.PP
As delivery proceeds, Exim writes timestamped information about each
address to a per-message log file; this includes any delivery error
messages. This log is solely for the benefit of the administrator. All
the information Exim itself needs for delivery is kept in the header
spool file. The message log file is deleted with the spool files. If a
message is delayed for more than a configured time, a warning message
is sent to the sender. This is repeated whenever the same time elapses
again without delivery being complete.
.PP
The main delivery processing elements of Exim are called directors,
routers, and transports. Code for a number of these is provided, and
compile-time options specify which ones are actually included in the
binary. Directors handle addresses that include one of the local
domains, routers handle remote addresses, and transports do actual
deliveries.
.SH TRUSTED AND ADMIN USERS
Some Exim options are available only to "trusted users" and others are
available only to "admin users".
.PP
A trusted user is root or the Exim user (if defined) or any user
listed in the trusted_users configuration option, or any user, if the
currently set group is one of those listed in the trusted_groups
configuration option. Trusted users are permitted to use the -f option
to specify the senders of messages that are passed to Exim through the
local interface, and also to specify host names, host addresses,
protocol names, and ident values. Thus they are able to insert
messages into Exim's queue locally that have the characteristics of
messages received from a remote host.
.PP
An admin user is root or the Exim user (if defined) or any user that
is a member of the Exim group (if defined). The current group does not
have to be the Exim group. Admin users are permitted to operate on
messages in the queue, for example, to force delivery failures. It is
also necessary to be an admin user in order to see the full
information provided by the Exim monitor.
.SH OPTIONS
Exim's command options are as follows:
.TP
.B -bd
Run Exim as a daemon, awaiting incoming SMTP connections. This option
can be used only by an admin user. If either of the -d or -dm options
are set, the daemon does not disconnect from the controlling
terminal. By default, Exim listens for incoming connections on all the
host's interfaces, but it can be restricted to specific interfaces by
setting the local_interfaces option in the configuration file. The
standard SMTP port is used, but this can be varied by means of the -oX
option. Most commonly, the -bd option is combined with the -q<time>
option, to cause periodic queue runs to happen as well.

The process id of a daemon that is both listening and starting queue
runners is written to a file called exim-daemon.pid in Exim's spool
directory, unless the -oX option is used, in which case the file
name is exim-daemon.<port-number>.pid. If a daemon is run with only
one of -bd and -q<time>, then that option is added on to the end of
the file name, allowing sites that run two separate daemons to
distinguish them.

It is possible to change the directory in which these pid files are
written by changing the setting of PID_FILE_PATH in Local/Makefile.
Further details are given in the comments in src/EDITME.

The SIGHUP signal can be used to cause the daemon to re-exec itself.
This should be done whenever Exim's configuration file is changed,
or a new version of Exim is installed. It is not necessary to do
this when other files (e.g. alias files) are changed.
.TP
.B -bf <filename>
Run Exim in filter testing mode; the file is the filter file to be
tested, and a test message must be supplied on the standard input.
If there are no message-dependent tests in the filter, an empty file
can be supplied. If the test file does not begin with the special
line

 # Exim filter

then it is taken to be a normal .forward file, and is tested for
validity under that interpretation. The result of this command,
provided no errors are detected, is a list of the actions that Exim
would try to take if presented with the message for real. More
details of filter testing are given in the separate document
entitled "Exim's User interface to mail filtering".

When testing a filter file, various parameters that would normally
be taken from the envelope recipient address of a message can be set
by means of additional command line options. These are:

 -bfd  <domain>    default is the qualify domain
 -bfl  <local_part>default is the logged in user
 -bfp  <local_part_prefix> default is null
 -bfs  <local_part_suffix> default is null

The local part should always be set to the incoming address with any
prefix or suffix stripped, because that is how it appears when a
message is actually being delivered.
.TP
.B -bi
Sendmail interprets the -bi option as a request to rebuild its alias
file. Exim does not have the concept of a single alias file, and so
it cannot mimic this behaviour. However, calls to /usr/lib/sendmail
-bi tend to appear in various scripts such as NIS make files, so the
option must be recognized.

If -bi is encountered, the command specified by the bi_command
configuration option is run, under the uid and gid of the caller of
Exim. If the -oA option is used, its value is passed to the command
as an argument. The command set by bi_command may not contain
arguments. The command can use the exim_dbmbuild utility, or some
other means, to rebuild alias files if this is required. If the
bi_command option is not set, then calling Exim with -bi is a no-op.
.TP
.B -bm
Accept an incoming, locally-generated message on the current input,
and deliver it to the addresses given as the command arguments
(except when -t is also given - see below). Each argument can be a
comma-separated list of RFC 822 addresses. This is the default
option, and is assumed if no other conflicting option is present.
The message may or may not be delivered immediately, depending on
the setting of the -od option and the queue_only and queue_smtp
configuration options.

The format of the message must be as defined in RFC 822, except
that, for compatibility with sendmail and smail, a line of the form

 From sender Fri Jan  5 12:55 GMT 1996

is permitted to appear at the start of the message. The Solaris 2
version of the "mail" command inserts such a line, though there is
no mention of it in the sendmail man page. The sender specified in
this line is treated as if it were given as the argument to the -f
option.
.TP
.B -bp
List the contents of the mail queue on the current output. Each
message on the queue is displayed as in the following example:

 25m  2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.book>
   red.king@looking-glass.fict.book
   <other addresses>

The first line contains the amount of time the message has been on
the queue (in this case 25 minutes), the size of the message (2.9K),
the unique identifier for the message, and the message sender, as
contained in the envelope. If the message is a delivery error
message, the sender address is empty, and appears as <>. If the
message is frozen (attempts to deliver it are suspended) then the
text '*** frozen ***' is displayed at the end of this line.

The recipients of the message (taken from the envelope, not the
headers) are displayed on subsequent lines. Those addresses to which
the message has already been delivered are marked with the letter D.
If an original address gets expanded into several addresses via an
alias or forward file, the original is displayed with a 'D' when
deliveries for all of its child addresses are completed.
.TP
.B -bP
If this option is given with no arguments, it causes the values of
all Exim's main configuration options to be written to the standard
output. The values of one or more specific options can be requested
by giving their names as arguments, for example:

 exim -bP qualify_domain local_domains

If configure_file is given, the name of the runtime configuration
file is output. If log_file_path or pid_file_path are given, the
names of the directories where log files and daemon pid files are
written are output, respectively. If these values are unset, log
files are written in a subdirectory of the spool directory called
log, and pid files are written directly into the spool directory.

If one of the words director, router, or transport is given,
followed by the name of an appropriate driver instance, the option
settings for that driver are output. For example:

 exim -bP transport local_delivery

The generic driver options are output first, followed by the
driver's private options. A list of the names of drivers of a
particular type can be obtained by using one of the words
director_list, router_list, or transport_list, and a complete list
of all drivers with their option settings can be obtained by using
directors, routers, or drivers.
.TP
.B -brt
This option is for testing retry rules, and it must be followed by
up to three arguments. It causes Exim to look for a retry rule that
matches the values and to output it on the standard output. For
example:

 exim -brt bach.comp.mus
 Retry rule: *.comp.mus  F,2h,15m; FG,4d,30m;

See chapter 30 for a description of Exim's retry rules. The first
argument, which is required, can be a complete address in the form
local_part@domain, or it can be just a domain name. The second
argument is an optional second domain name; if no retry rule is
found for the first argument, the second is tried. This ties in with
Exim's behaviour when looking for retry rules for remote hosts - if
no rule is found that matches the host, one that matches the mail
domain is sought. The final argument is the name of a specific
delivery error, as used in setting up retry rules, for example
'quota_3d'.
.TP
.B -brw
This option is for testing address rewriting rules, and it must be
followed by a single argument, consisting of either a local part
without a domain, or a complete address with a fully-qualified
domain. Exim outputs how this address would be rewritten for each
possible place it might appear.
.TP
.B -bS
This option is used for batched SMTP input, where messages have been
received from some external source by an alternative transport
mechanism. It causes Exim to accept one or more messages by reading
SMTP on the standard input, but to generate no responses. All errors
are reported by sending mail. If the caller is trusted, then the
senders in the MAIL FROM commands are believed; otherwise the sender
is always the caller of Exim. Unqualified senders and receivers are
not rejected (there seems little point) but instead just get
qualified. Receiver verification and administrative rejection is not
done, even if configured. HELO and EHLO act as RSET; VRFY, EXPN, ETRN,
HELP, and DEBUG act as NOOP; QUIT quits.
.TP
.B -bs
This option causes Exim to accept one or more messages by reading SMTP
commands on the standard input, and producing SMTP replies on the
standard output. Some user agents use this interface as a way of
passing locally-generated messages to the MTA. The option can also be
used to run Exim from inetd, as an alternative to using a listening
daemon, in which case the standard input is the connected socket. Exim
distinguishes between the two cases by attempting to read the IP
address of the peer connected to the standard input. If it is not a
socket, the call to getpeername() fails, and Exim assumes it is
dealing with a local message.

If the caller of Exim is trusted, then the senders of messages are
taken from the SMTP MAIL FROM commands. Otherwise the content of these
commands is ignored and the sender is set up as the calling user.
.TP
.B -bt
Run in address testing mode, in which each argument is taken as an
address to be tested. The results are written to the standard
output. If no arguments are given, Exim runs in an interactive manner,
prompting with > for addresses to be tested. Each address is handled
as if it were the recipient address on a message and passed to the
appropriate directors or routers.
.TP
.B -bV
Write the current version number, compilation number, and compi-
lation date of the exim binary to the standard output.
.TP
.B -bv
Verify the addresses that are given as the arguments to the command,
and write the results to the standard output. Verification differs
from address testing (the -bt option) in that directors and routers
that have no_verify set are skipped, and if the address is accepted by
a director or router that has fail_verify set, verification
fails. This is the same logic that is used when verifying addresses on
incoming messages (see the sender_verify and receiver_verify options).

If the -v (or -d) option is not set, the output consists of a single
line for each address, stating whether it was verified or not, and
giving a reason in the latter case. Otherwise, more details are given
of how the address has been handled, and in the case of aliases or
forwarding, the generated addresses are also considered.
.TP
.B -C <filename>
Read the runtime configuration from the given file instead of from
the default file specified by the CONFIGURE_FILE compile-time set-
ting. When this option is used by an unprivileged caller, Exim gives
up its root privilege immediately, and runs with the real and
effective uid and gid set to those of the caller, to avoid any
security exposure. It does not do this if the caller is root or the
exim user. The facility is useful for ensuring that configuration
files are syntactically correct, but cannot be used for test
deliveries, unless the caller is privileged, or unless it's an
exotic configuration that does not require privilege. No check is
made on the owner or group of the file specified by this option.
.TP
.B -d<number>
Sets a debug level, causing debugging information to be written to the
standard error file. Whitespace between -d and the number is
optional. If no number is given, 1 is assumed, and the higher the
number, the more output is produced. A value of zero turns debugging
output off. A value of 9 gives the maximum amount of general
information, 10 gives in addition details of the interpretation of
filter files, and 11 or higher also turns on the debugging option for
DNS lookups.
.TP
.B -df
If this option is set and STDERR_FILE was defined when Exim was built,
debugging information is written to the file defined by that variable
instead of to the standard error file. This option provides a way of
obtaining debugging information when Exim is run from inetd.
.TP
.B -dm
This option causes information about memory allocation and freeing
operations to be written to the standard error file.
.TP
.B -E
This option specifies that an incoming message is a locally-generated
delivery failure message. It is used internally by Exim when handling
delivery failures and is not intended for external use. Its only
effect is to stop Exim generating certain messages to the mailmaster,
as otherwise message cascades could occur in some situations. As part
of the same option, a message id may follow the characters -E. If it
does, the log entry for the receipt of the new message contains the
id, following 'R=', as a cross reference.
.TP
.B -ex
There are a number of sendmail options starting with -oe which seem to
be called by various programs without the leading o in the option. For
example, the vacation program uses -eq. Exim treats all options of the
form -ex as synonymous with the corresponding -oex options.
.TP
.B -F <string>
Set the sender's full name for use when a locally-generated message
is being accepted. In the absence of this option, the user's "gecos"
entry from the password file is used. As users are generally
permitted to alter their "gecos" entries, no security considerations
are involved. White space between -F and the <string> is optional.
.TP
.B -f <address>
Set the address of the sender of a locally-generated message. This
option can normally be used only by root or the Exim user or by one
of the configured trusted users. In other cases, the sender of a
local message is always set up as the user who ran the exim command,
and -f is ignored, with one exception. If the special setting -f <>
is used by an untrusted user, it does not affect the sender for the
purposes of managing the Sender: and From: headers, but it does have
the effect of causing any SMTP transmissions to be sent out with

 MAIL FROM: <>

and local deliveries to contain

 Return-path: <>

when configured to contain Return-path: headers. The filtering code
treats such a message as an error message, and won't generate
messages as a result of reading it.

White space between -f and the <string> is optional. The sender of a
locally-generated message can also be set by an initial 'From' line
in the message - see the description of -bm above.
.TP
.B -h <number>
This option is accepted for compatibility with sendmail, but at
present has no effect. (In sendmail it overrides the 'hop count'
obtained by counting Received headers.)
.TP
.B -i
This option, which has the same effect as -oi, specifies that a dot
on a line by itself should not terminate an incoming, non-SMTP
message. I can find no documentation for this option in Solaris 2.4
sendmail, but the mailx command in Solaris 2.4 uses it.
.TP
.B -M
The arguments are interpreted as a list of message ids, and Exim runs
a delivery attempt on each message in turn. Retry hints for any of the
addresses are overridden - this option forces Exim to try to deliver
even if the normal retry time has not yet been reached. If any of the
messages is frozen, it is automatically thawed before the delivery
attempt, provided that the caller is an admin user.
.TP
.B -Mar <message-id> <address> <address> ...
The first argument must be a message id, and the remaining ones must
be email addresses. Exim adds the addresses to the list of recipi-
ents of the message. However, if the message is active (in the middle
of a delivery attempt), its status is not altered. This option can be
used only by an admin user.
.TP
.B -Meb <message-id>
This runs, under /bin/sh, the command defined in the shell variable
VISUAL or, if that is not defined, EDITOR or, if that is not defined,
the command vi, on a copy of the spool file containing the body of
message (eb = Edit Body). If the editor exits normally, then the
result of editing replaces the spool file. The message is locked
during this process, so no delivery attempts can occur. Note that the
first line of the spool file is its own name; care should be taken not
to disturb this. The thinking behind providing this feature is that an
administrator who has had to mess around with the addresses to get a
message delivered might want to add some (grumbly) comment at the
start of the message text. This option can be used only by an admin
user.
.TP
.B -Mes <message-id> <address>
There must be exactly two arguments. The first argument must be a
message id, and the second one an email address. Exim changes the
sender address in the message to the given address, which must be a
fully qualified address, or '<>'. However, if the message is active
(in the middle of a delivery attempt), its status is not altered.
This option can be used only by an admin user.
.TP
.B -Mmad <message-id>
Exim marks the all recipient addresses in the message as already
delivered. However, if the message is active (in the middle of a
delivery attempt), its status is not altered. This option can be used
only by an admin user.
.TP
.B -Mmd <message-id> <address> <address> ...
The first argument must be a message id, and the remaining ones must
be email addresses. Exim marks the given addresses as already
delivered. However, if the message is active (in the middle of a
delivery attempt), its status is not altered. This option can be used
only by an admin user.
.TP
.B -MC <transport> <hostname> <sequence number> <message id>
This option is not intended for use by outside callers. It is used
internally by Exim to invoke another instance of itself to deliver a
waiting message using an existing SMTP channel, which is passed as the
standard input and output. Details are given in chapter 43. This must
be the final option, and the caller must be root or the Exim user in
order to use it.
.TP
.B -Mc
The arguments are interpreted as a list of message ids, and Exim runs
a delivery attempt on each message in turn, but unlike the -M option,
it does check for retry hints, and respects any that are found. This
option is not very useful to external callers (except for testing). It
is provided for internal use by Exim when it needs to re-invoke itself
in order to regain root privilege for a delivery (see chapter 44).
.TP
.B -Mf
The arguments are interpreted as a list of message ids, and each
message is marked 'frozen'. This prevents any delivery attempts taking
place until the message is 'thawed', either manually or as a result of
the auto_thaw configuration option. However, if any of the messages is
active (in the middle of a delivery attempt), its status is not
altered. This option can be used only by an admin user.
.TP
.B -Mg
The arguments are interpreted as a list of message ids, and Exim gives
up trying to deliver those messages. A delivery error message is sent,
containing the text 'cancelled by administrator'. However, if any of
the messages is active, its status is not altered. This option can be
used only by an admin user.
.TP
.B -Mt
The arguments are interpreted as a list of message ids, and each
message that was 'frozen' is now 'thawed', so that delivery attempts
can resume. However, if any of the messages is active, its status is
not altered. This option can be used only by an admin user.
.TP
.B -Mrm
The arguments are interpreted as a list of message ids, and each
message is completely removed from Exim's queue, and forgotten.
However, if any of the messages is active, its status is not
altered. This option can be used only by an admin user or by the user
who originally caused the message to be placed on the queue.
.TP
.B -m
This is apparently a synonym for -om that is accepted by sendmail, so
Exim treats it that way too.
.TP
.B -N
This is a debugging option that inhibits delivery of a message at the
transport level. It implies at least -d1. Exim goes through many of
the motions of delivery - it just doesn't actually transport the
message, but instead behaves as if it had successfully done so. The
log, for example, will contain entries as if the message had been
delivered. Only root or the exim user are allowed to use -N with -bd,
-q, or -M. In other words, an ordinary user can use it only when
supplying an incoming message.
.TP
.B -oA <file name>
This option is used by Sendmail in conjunction with -bi to specify an
alternative alias file name. Exim handles -bi differently; see the
description above.
.TP
.B -oB <n>
This is a debugging option which limits the maximum number of SMTP
deliveries down one channel to <n>, overriding the value set in the
smtp transport. If <n> is omitted, the limit is set to 1 (no
batching).
.TP
.B -odb
This option applies to all modes in which Exim accepts incoming
messages, including the listening daemon. It requests 'background'
delivery of such messages, which means that the accepting process
automatically starts another delivery process for each message
received. Exim does not wait for such processes to complete (it can
take some time to perform SMTP deliveries). This is the default action
if none of the -od options are present.
.TP
.B -odf
This option (compatible with smail) requests 'foreground' (syn-
chronous) delivery when Exim has accepted a locally-generated mess-
age. For the daemon it is exactly the same as -odb. For a single
message received on the standard input, if the protection regime
permits it (see chapter 44), Exim converts the reception process into
a delivery process. In other cases, it creates a new delivery process,
and then waits for it to complete before proceeding.
.TP
.B -odi
This option is synonymous with -odf. It is provided for compati-
bility with sendmail.
.TP
.B -odq
This option applies to all modes in which Exim accepts incoming
messages, including the listening daemon. It specifies that the
accepting process should not automatically start a delivery attempt
for each message received. Messages are placed on the queue, and
remain there until a subsequent queue-running process encounters
them. The queue_only configuration option has the same effect.
.TP
.B -odqr
This option applies to all modes in which Exim accepts incoming
messages, including the listening daemon. It causes Exim to process
local addresses when a message is received, but not even to try
routing remote addresses. Contrast with -odqs below, which does the
routing, but not the delivery. The remote addresses will be picked up
by the next queue runner. The queue_remote configuration option has
the same effect.
.TP
.B -odqs
This option is a hybrid between -odb and -odq. A delivery process is
started for each incoming message, the addresses are all processed,
and local deliveries are done in the normal way. However, if any SMTP
deliveries are required, they are not done at this time. Such messages
remain on the queue until a subsequent queue-running process
encounters them. Because routing was done, Exim knows which messages
are waiting for which hosts, and so a number of messages for the same
host will get sent in a single SMTP connection. The queue_smtp
configuration option has the same effect.
.TP
.B -oem
If an error is detected while a non-SMTP message is being received
(e.g. a malformed address), the error is reported to the sender in a
mail message. This is the default option. After a message has been
successfully received, any subsequent delivery errors are always
reported in this way.
.TP
.B -oep
If an error is detected while a non-SMTP message is being received,
the error is reported by writing a message to the standard error file
(stderr).
.TP
.B -oeq
This option is supported for compatibility with sendmail, but has the
same effect as -oep.
.TP
.B -oew
This option is supported for compatibility with sendmail, but has the
same effect as -oem.
.TP
.B -oi
This option, which has the same effect as -i, specifies that a dot on
a line by itself should not terminate an incoming, non-SMTP message.
.TP
.B -oMa <host address>
This option sets the sender host address value, and can be used only
by a trusted caller. The value is used in log entries and can appear
in Received headers. The option is intended for use when handing to
Exim messages received by other means.
.TP
.B -oMr <protocol name>
This option sets the received protocol value, and can be used only by
a trusted caller. The value is used in log entries and can appear in
Received headers. The option is intended for use when handing to Exim
messages received by other means.
.TP
.B -oMs <host name>
This option sets the sender host name value, and can be used only by a
trusted caller. The value is used in log entries and can appear in
Received headers. The option is intended for use when handing to Exim
messages received by other means.
.TP
.B -oMt <ident string>
This option sets the sender ident value, and can be used only by a
trusted caller. The value is used in log entries and can appear in
Received headers. The option is intended for use when handing to Exim
messages received by other means.
.TP
.B -om
In sendmail, this option means 'me too', indicating that the sender of
a message should receive a copy of the message if the sender appears
in an alias expansion. Exim always does this, so the option does
nothing.
.TP
.B -or <time>
This option sets a timeout value for incoming non-SMTP messages. If it
is not set, Exim will wait forever for the standard input. The value
can also be set using the accept_timeout configuration vari- able. The
format used for specifying times is described in section 7.6.
.TP -ov
This option has exactly the same effect as -v.
.TP
.B -oX <number>
This option is relevant only when the -bd option is also given. It
specifies an alternative TCP/IP port number for the listening daemon,
and is useful for testing. When used, the process number of the daemon
is written to a file whose name is exim- daemon.<number>.pid in Exim's
spool directory.
.TP
.B -q
If the -q option is not followed by a time value, it requests a single
queue run operation. This option can be used only by an admin
user. Exim starts up a delivery process for each (inactive) message on
the queue in turn, and waits for it to finish before starting the next
one. When all the queued messages have been considered, the original
process terminates. In other words, a single pass is made over the
waiting mail. Use -q with a time (see below) if you want this to be
repeated periodically.

Exim processes the waiting messages in an unpredictable order. It
isn't very random, but it is likely to be different each time, which
is all that matters. If one particular message screws up a remote MTA,
other messages to the same MTA have a chance of getting through if
they get tried first.

However, it is possible to cause the messages to be processed in
lexical id order, which is essentially the order in which they
arrived, and to start this operation at a particular point by
following the -q option with a starting message id. For example:

 exim -q 0t5C6f-0000c8-00

This causes Exim to skip any messages whose ids are lexically less
than the given id. A second id can also be given to stop the queue run
before the end. See also the -R option.
.TP
.B -q <time>
This version of the -q option (which again can be run only by an admin
user) causes Exim to run as a daemon, starting a queue-running process
at intervals specified by the given time value (whose format is
described in section 7.6). This form of the -q option is commonly
combined with the -bd option, in which case a single daemon process
handles both functions. A common way of starting up a combined daemon
at system boot time is to use a command such as

 /opt/exim/bin/exim -bd -q30m

Such a daemon listens for incoming SMTP calls, and also fires up a
queue-runner process every 30 minutes. The process id of such a daemon
is written to a file called exim-daemon.pid in Exim's spool directory,
unless the -oX option has been used, in which case the file is called
exim-daemon.<port-number>.pid. The location of the pid file can be
changed by defining PID_FILE_PATH in Local/Makefile.  If a daemon is
started without -bd then the -q option used to start it is added to
the pid file name.
.TP
.B -qf
This option operates like -q, and may appear with or without a
following time. The difference is that a delivery attempt is forced
for each message, whereas with -q only those addresses that have
passed their retry times are tried.
.TP
.B -qfl
This option operates like -ql, and may appear with or without a
following time. The difference is that a delivery attempt is forced
for each message, whereas with -ql only those local addresses that
have passed their retry times are tried.
.TP
.B -ql
This option operates like -q, and may appear with or without a
following time. The difference is that only local addresses are
considered for delivery. Note that -ql cannot detect apparently remote
addresses that actually turn out to be local when their domains get
fully qualified.
.TP -R <string>
This option is similar to -q with no time value, except that, when
scanning the messages on the queue, Exim processes only those that
have at least one undelivered address containing the given string,
which is checked in a case-independent way. However, once a message is
selected, all its addresses are processed. For the first message
containing a matching address, Exim overrides any retry information
and forces a delivery attempt. This makes it straightforward to
initiate delivery for all messages to a given domain after a host has
been down for some time. When the SMTP command ETRN is permitted (see
the smtp_etrn options), its effect is to run Exim with the -R option.
.TP
.B -r
This is a documented (for sendmail) obsolete alternative name for -f.
.TP
.B -t
When Exim is receiving a locally-generated, non-SMTP message on the
current input, the -t option causes the recipients of the message to
be obtained from the To, Cc, and Bcc headers in the message instead of
from the command arguments. If there are any arguments, they specify
addresses to which the message is not to be delivered. That is, the
argument addresses are removed from the recipients list obtained from
the headers. If a Bcc header is present, it is removed from the
message unless there is no To or Cc header, in which case a Bcc header
with no data is created, in accordance with RFC 822.
.TP
.B -v
This option has exactly the same effect as -d1; it causes Exim to be
'verbose' and produce some output describing what it is doing on the
standard error file. In particular, if an SMTP connection is made, the
SMTP dialogue is shown.
.TP
.B -x
AIX uses -x for a private purpose ('mail from a local mail program has
National Language Support extended characters in the body of the mail
item'). It sets -x when calling the MTA from its mail command.  Exim
ignores this option.
.SH "SEE ALSO"
sendmail(8), mailwrapper(8), mailer.conf(5).
.SH AUTHOR
This manual page was stitched together by Christoph Lameter,
<clameter@debian.org>, from the original documentation coming with the
sourcepackage for the Debian GNU/Linux system, and cleaned up a little
by Tim Cutts <tjrc1@scalopus.bio.cam.ac.uk>. Modifications for NetBSD
made by Andy Doran <ad@NetBSD.org>.