itprojectsllc/postfix-docker repository overview

stripped down postfix container designed for linking to docker containers.

minimal image running postfix and rsyslog. configured to relay for other docker containers (on docker's 172.17.0.0/16 range).

So, you would run it with something like:

$ docker run --name=postfix -e MAILNAME=mail.myserver.com \
  localhost:5000/ccnmtl/postfix

Then, if you had, say a Django app container that you wanted to be able to send mail, you would link it with:

$ docker run -P --link=postfix:postfix mydjangoapp

The environment variables POSTFIX_PORT_25_TCP_ADDR and POSTFIX_PORT_25_TCP_PORT in your django container would then contain the correct IP/port combo for in internal link to the postfix container. So you would configure your django app to send SMTP requests there.

This was inspired by catatnight/docker-postfix⁠ but we took out the TLS/OpenDKIM stuff and made it a bit simpler to link.