+
. /////////////////////////////////////////////////////////////////////////////
. This is the primary source of the Exim Manual. It is an xfpt document that is
. converted into DocBook XML for subsequent conversion into printable and online
.cindex "base36"
.cindex "Darwin"
.cindex "Cygwin"
+.cindex "exim_msgdate"
Every message handled by Exim is given a &'message id'& which is sixteen
characters long. It is divided into three parts, separated by hyphens, for
example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
pid, it is guaranteed that the time will be different. In most cases, the clock
will already have ticked while the message was being received.
+The exim_msgdate utility (see section &<<SECTexim_msgdate>>&) can be
+used to display the date, and optionally the process id, of an Exim
+Message ID.
+
.section "Receiving mail" "SECID13"
.cindex "receiving mail"
referenced from the configuration (for example, alias files) are changed,
because these are reread each time they are used.
+.new
+Either a SIGTERM or a SIGINT signal should be used to cause the daemon
+to cleanly shut down.
+Subprocesses handling recceiving or delivering messages,
+or for scanning the queue,
+will not be affected by the termination of the daemon process.
+.wen
+
.cmdopt -bdf
This option has the same effect as &%-bd%& except that it never disconnects
from the controlling terminal, even when no debugging is specified.
&%queue_list_requires_admin%& is set false.
+.cmdopt -bpi
+.cindex queue "list of message IDs"
+This option operates like &%-bp%&, but only outputs message ids
+(one per line).
+
+
.cmdopt -bpr
This option operates like &%-bp%&, but the output is not sorted into
chronological order of message arrival. This can speed it up when there are
.cmdopt -bpra
This option is a combination of &%-bpr%& and &%-bpa%&.
+.cmdopt -bpri
+This option is a combination of &%-bpr%& and &%-bpi%&.
+
.cmdopt -bpru
This option is a combination of &%-bpr%& and &%-bpu%&.
given.
Normally the daemon creates this socket, unless a &%-oX%& and &*no*& &%-oP%&
option is also present.
-If this option is given then the socket will not be created. This could be
-required if the system is running multiple daemons.
+.new
+If this option is given then the socket will not be created. This is required
+if the system is running multiple daemons, in which case it should
+be used on all.
+The features supported by the socket will not be available in such cases.
The socket is currently used for
.ilist
fast ramp-up of queue runner processes
.next
+caching compiled regexes
+.next
obtaining a current queue size
.endlist
+.wen
.cmdopt -pd
.cindex "Perl" "starting the interpreter"
transports are run.
Performance will be best if the &%queue_run_in_order%& option is false.
-If that is so and the &%queue_fast_ramp%& option is true then
-in the first phase of the run,
+If that is so and
+the &%queue_fast_ramp%& option is true
+and a daemon-notifier socket is available
+then in the first phase of the run,
once a threshold number of messages are routed for a given host,
a delivery process is forked in parallel with the rest of the scan.
.cindex "hints database" "remembering routing"
The hints database that remembers which messages are waiting for specific hosts
-is updated, as if delivery to those hosts had been deferred. After this is
-complete, a second, normal queue scan happens, with routing and delivery taking
-place as normal. Messages that are routed to the same host should mostly be
+is updated, as if delivery to those hosts had been deferred.
+
+After the first queue scan complete,
+a second, normal queue scan is done, with routing and delivery taking
+place as normal.
+Messages that are routed to the same host should mostly be
delivered down a single SMTP
.cindex "SMTP" "passed connection"
.cindex "SMTP" "multiple deliveries"
.cindex "multiple SMTP deliveries"
connection because of the hints that were set up during the first queue scan.
-This option may be useful for hosts that are connected to the Internet
+
+.new
+Two-phase queue runs should be used on systems which, even intermittently,
+have a large queue (such as mailing-list operators).
+They may also be useful for hosts that are connected to the Internet
intermittently.
+.wen
.vitem &%-q[q]i...%&
.oindex "&%-qi%&"
Such a daemon listens for incoming SMTP calls, and also starts a queue runner
process every 30 minutes.
+.new
+.cindex "named queues" "queue runners"
+It is possible to set up runners for multiple named queues within one daemon,
+For example:
+.code
+exim -qGhipri/2m -q10m -qqGmailinglist/1h
+.endd
+.wen
+
When a daemon is started by &%-q%& with a time value, but without &%-bd%&, no
pid file is written unless one is explicitly requested by the &%-oP%& option.
+.new
+.vitem &*${headerwrap_*&<&'cols'&>&*_*&<&'limit'&>&*:*&<&'string'&>&*}*&
+.cindex header "wrapping operator"
+.cindex expansion "header wrapping"
+This operator line-wraps its argument in a way useful for headers.
+The &'cols'& value gives the column number to wrap after,
+the &'limit'& gives a limit number of result characters to truncate at.
+Either just the &'limit'& and the preceding underbar, or both, can be omitted;
+the defaults are 80 and 998.
+Wrapping will be inserted at a space if possible before the
+column number is reached.
+Whitespace at a chosen wrap point is removed.
+A line-wrap consists of a newline followed by a tab,
+and the tab is counted as 8 columns.
+.wen
+
+
+
.vitem &*${hex2b64:*&<&'hexstring'&>&*}*&
.cindex "base64 encoding" "conversion from hex"
.cindex "expansion" "hex to base64"
.cindex TLS "EC cryptography"
This option selects EC curves for use by Exim when used with OpenSSL.
It has no effect when Exim is used with GnuTLS
- (the equivalent can be done using a priority string for the
+(the equivalent can be done using a priority string for the
&%tls_require_ciphers%& option).
After expansion it must contain
Note that Dovecot must be configured to use auth-client not auth-userdb.
If you are using Dovecot to authenticate POP/IMAP clients, it might be helpful
to use the same mechanisms for SMTP authentication. This is a server
-authenticator only. There is only one option:
+authenticator only. There is only one non-generic option:
.option server_socket dovecot string unset
dovecot_plain:
driver = dovecot
public_name = PLAIN
+ server_advertise_condition = ${if def:tls_in_cipher}
server_socket = /var/run/dovecot/auth-client
server_set_id = $auth1
server_socket = /var/run/dovecot/auth-client
server_set_id = $auth1
.endd
+
+.new
+&*Note*&: plaintext authentication methods such as PLAIN and LOGIN
+should not be advertised on cleartext SMTP connections.
+See the discussion in section &<<SECTplain_TLS>>&.
+.wen
+
If the SMTP connection is encrypted, or if &$sender_host_address$& is equal to
&$received_ip_address$& (that is, the connection is local), the &"secured"&
option is passed in the Dovecot authentication command. If, for a TLS
.next
The way with most moving parts at query time is Online Certificate
Status Protocol (OCSP), where the client verifies the certificate
-against an OCSP server run by the CA.
-OCSP is based on HTTP and can be proxied accordingly.
-It requires the CA running software with access to the
-private key of the CA, to sign the responses to the OCSP queries.
-Because every client TLS transaction with a server results in an OCSP
-access to the CA, it results in a heavy load on the CA.
-It also lets the CA track all usage of the certs, which is a privacy problem.
+against an OCSP server run by the CA. This lets the CA track all
+usage of the certs. It requires running software with access to the
+private key of the CA, to sign the responses to the OCSP queries. OCSP
+is based on HTTP and can be proxied accordingly.
The only widespread OCSP server implementation (known to this writer)
comes as part of OpenSSL and aborts on an invalid request, such as
.next
The third way is OCSP Stapling; in this, the server using a certificate
issued by the CA periodically requests an OCSP proof of validity from
-the OCSP server (probably using the original OCSP above),
-then serves it up inline as part of the TLS
+the OCSP server, then serves it up inline as part of the TLS
negotiation. This approach adds no extra round trips, does not let the
CA track users, scales well with number of certs issued by the CA and is
resilient to temporary OCSP server failures, as long as the server
.irow &<<SECTtidydb>>& &'exim_tidydb'& "clean up a hints database"
.irow &<<SECTfixdb>>& &'exim_fixdb'& "patch a hints database"
.irow &<<SECTmailboxmaint>>& &'exim_lock'& "lock a mailbox file"
+.irow &<<SECTexim_msgdate>>& &'exim_msgdate'& "Message Ids for humans (exim_msgdate)"
.endtable
Another utility that might be of use to sites with many MTAs is Tom Kistner's
.endd
Note that if a command is supplied, it must be entirely contained within the
second argument &-- hence the quotes.
-.ecindex IIDutils
+.section "Message Ids for humans (exim_msgdate)" "SECTexim_msgdate"
+.cindex "exim_msgdate"
+The &'exim_msgdate'& utility is written by Andrew Aitchison and included in the Exim distribution.
+This Perl script converts an Exim Mesage ID back into a human readable form.
+For details of &'exim_msgdate'&'s options, run &'exim_msgdate'& with the &%--help%& option.
+
+Section &<<SECTmessiden>>& (Message identification) describes Exim Mesage IDs.
+.ecindex IIDutils
. ////////////////////////////////////////////////////////////////////////////
. ////////////////////////////////////////////////////////////////////////////
# one, plus the max_rcpt and return_path options
remote_forwarded_smtp:
driver = smtp
- # modify the envelope from, for mails that we forward
+ # single-recipient so that $original_domain is valid
max_rcpt = 1
+ # modify the envelope from, for mails that we forward
return_path = ${srs_encode {SRS_SECRET} {$return_path} {$original_domain}}
.endd