This is a Dockerfile for a basic postfix/courier server. Currently it's just for incoming emails and just has a single mailbox.
Generate your DKIM key and place the private in ./opendkim.private
Assuming docker is installed:
./build.sh
This will download and build the image to run, if you make any changes then re-run.
./start.sh
This will create an instance and run it. The password is injected via environment variables.