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.