16.5.1 To Configure Back End Stores with LMTP and a Minimal MTA

The back end stores require only a minimal MTA if they are receiving messages over LMTP. They require a dispatcher, a job controller and a simple MTA configuration. In particular they need a dispatcher.cnf, job_controller.cnf and a mappings file which comprise the only significant part of the MTA configuration.

The dispatcher.cnf file must contain the following:

! VERSION=1.1
! IMTA default dispatcher configuration file
!
! Global defaults
!
MIN_PROCS=1
MAX_PROCS=10
MIN_CONNS=30
MAX_CONNS=50
MAX_SHUTDOWN=2
MAX_LIFE_TIME=86400
MAX_LIFE_CONNS=10000
MAX_IDLE_TIME=600
HISTORICAL_TIME=0
!
! rfc 2033 LMTP server - store
!
[SERVICE=LMTPSS]
PORT=225
IMAGE=IMTA_BIN:tcp_lmtp_server
LOGFILE=IMTA_LOG:tcp_lmtpss_server.log
PARAMETER=CHANNEL=tcp_lmtpss
STACKSIZE=2048000
! Uncomment the following line and set INTERFACE_ADDRESS to an
! appropriate host IP (dotted quad) if the dispatcher needs to
! listen on a specific interface (e.g. in a HA environment).
! INTERFACE_ADDRESS=!
! rfc 2033 LMTP server - native
!

Note that by default, the LMTP services in the dispatcher.cnf file are commented out. You must uncomment them to get LMTP to work.

The normal dispatcher options of MAX_CONNS, MAX_PROCS, MAX_LIFE_CONNS, and MAX_LIFE_TIME can also be set, but need to be set appropriately for your hardware.

The PORT_ACCESS mapping is important. The LMTP implementation for the back end servers is intended as a private protocol between Sun Java System Messaging Server relays and back end stores. You must use the PORT_ACCESS mapping to make sure that only such relays can connect to these services. Your mapping file should look like this:

PORT_ACCESS

  TCP|*|225|192.18.74.206|* $Y
  TCP|*|226|192.18.74.206|* $Y
  TCP|*|225|192.18.74.129|* $Y
  TCP|*|226|192.18.74.129|* $Y
  TCP|*|*|*|*   $N500$ Do$ not$ connect$ to$ this$ machine

The IP address above are LMTP server and client IP address. You should replace the sample IP addresses specified in the PORT_ACCESS mapping table here with the IP addresses of your relays on the network that connect to the back end stores.

There has to be an imta.cnf file, but it is there merely to make the configuration complete. A minimal imta.cnf file consists of the following channel definitions:

!
! IMTA configuration file
!
! tcp_lmtpss (LMTP server - store)
tcp_lmtpss lmtp flagtransfer
tcp_lmtpss-daemon

Note that by default, the LMTP channel definitions are commented out. You must uncomment them if you want LMTP to work.

You can use the default job_controller.cnf file created on installation. No modification of this file is required.