Mailcatcher catches mail and serves it through a dream.
Run with : docker run -d -p 1025:1025 -p 1080:1080 --name mailcatcher jeanberu/mailcatcher
Deliver mails to smtp://127.0.0.1:1025 and check out http://127.0.0.1:1080 to see them.
To change options, replace Docker image default command. You can see option list here.
Example: docker run -d --expose 80 -p 80:80 -p 1025:1025 --name mailcatcher jeanberu/mailcatcher --ip=0.0.0.0 --http-port=80
Docker image's default options are: --ip=0.0.0.0.