lmtpproxyd - Cyrus IMAP documentation

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       1993–2025, The Cyrus Team

3.10.2                                            Jun 27, 2025                                     LMTPPROXYD(8)

lmtpd is an LMTP server used to deliver mail to the IMAP mailstore.  It accepts commands on its  standard
       input  and  responds  on  its  standard  output.  It  MUST be invoked by master(8) with those descriptors
       attached to a remote client connection.

       lmtpd reads its configuration options out of the imapd.conf(5) file unless specified otherwise by -C.

lmtpd is commonly included in the SERVICES section of cyrus.conf(5) like so:

          SERVICES {
              imap        cmd="imapd -U 30" listen="imap" prefork=0
              imaps       cmd="imapd -s -U 30" listen="imaps" prefork=0 maxchild=100
              lmtpunixcmd="lmtpd"listen="/var/run/cyrus/socket/lmtp"prefork=0maxchild=20
              sieve       cmd="timsieved" listen="sieve" prefork=0
              notify      cmd="notifyd" listen="/var/run/cyrus/socket/notify" proto="udp" prefork=1
              httpd       cmd="httpd" listen=8080 prefork=1 maxchild=20
          }

       /etc/imapd.conf

       lmtpproxyd - Cyrus IMAP documentation

       This  is a hard linked copy of lmtpd(8), retained for backwards compatibility from when a murder frontend
       used its own lmtpd binaries.

-Cconfig-file
              Use the specified configuration file config-file rather than the default imapd.conf(5).

       -Uuses
              The maximum number of times that the process should be used for new  connections  before  shutting
              down.  The default is 250.

       -Ttimeout
              The  number of seconds that the process will wait for a new connection before shutting down.  Note
              that a value of 0 (zero) will disable the timeout.  The default is 60.

       -D     Run external debugger specified in debug_command.

       -a     Preauthorize connections initiated on an internet socket, instead of requiring  LMTP  AUTH.   This
              should only be used for connections coming from trusted hosts.

imapd.conf(5), master(8)

lmtpd [ -Cconfig-file ]  [ -Uuses ] [ -Ttimeout ] [ -D ] [ -a ]