Simple SMTP relay, forked from shamil/docker-postfix-relay, which was originally based on alterrebe/docker-mail-relay.

The container provides a simple SMTP relay for environments like Amazon VPC where you may have private servers with no Internet connection and therefore with no access to external mail relays (e.g. Amazon SES, SendGrid and others). You need to supply the container with your external mail relay address and credentials. The image is tested with Amazon SES, Sendgrid, Gmail and Mandrill

• Uses alpine image instead of ubuntu.
• Uses envsubst for templating instead of j2cli.
• All output goes to stdout and stderr including maillog.
• Included superviserd event watcher which will exit the supervisord process if one of the monitored processes dies unexpectedly.
• Doesn't use TLS on smtpd side.
• And other changes to make the image as KISS as possible

• Remove rsyslog dependancy
• Remove supervisor
• Even more KISS, just single script used to configure and run postfix

Postfix on port 25

Launch Postfix container:

docker run -d -h relay.example.com --name="mailrelay" \
    -e RECIPIENT_RESTRICTIONS="gmail.com [email protected]" \
    -e SMTP_LOGIN=myLogin \
    -e SMTP_PASSWORD=myPassword \
    -p 25:25 \
    simenduev/postfix-relay