Simple postfix backup mailserver for your Docker containers. Based on Alpine Linux.
This image allows you to run POSTFIX internally inside your docker installation.
To run the container, do the following:
docker run --rm --name backup-mx -e "HOSTNAME=mx2.example.com -e DOMAINS=example.com,example2.com" -p 25:25 numero33/backup-mx
The following configuration options are available:
ENV vars
$HOSTNAME = Postfix myhostname
$DOMAINS = Domains for relaying
Postfix will try to deliver emails asap to the primary server.
Postfix will run the master proces as root, because that's how it's designed. Subprocesses will run under the postfix account
which will use UID:GID of 100:101.