run postfix with smtp authentication (sasldb) in a docker container. TLS and OpenDKIM support are optional.

• Docker 1.0

1. Build image

   $ sudo docker pull catatnight/postfix

1. Create postfix container with smtp authentication

   $ sudo docker run -p 25:25 \
   		-e maildomain=mail.example.com -e smtp_user=user:pwd \
   		--name postfix -d catatnight/postfix
   # Set multiple user credentials: -e smtp_user=user1:pwd1,user2:pwd2,...,userN:pwdN

2. Enable OpenDKIM: save your domain key .private in /path/to/domainkeys

   $ sudo docker run -p 25:25 \
   		-e maildomain=mail.example.com -e smtp_user=user:pwd \
   		-v /path/to/domainkeys:/etc/opendkim/domainkeys \
   		--name postfix -d catatnight/postfix

3. Enable TLS(587): save your SSL certificates .key and .crt to /path/to/certs

   $ sudo docker run -p 587:587 \
   		-e maildomain=mail.example.com -e smtp_user=user:pwd \
   		-v /path/to/certs:/etc/postfix/certs \
   		--name postfix -d catatnight/postfix

• Login credential should be set to (username@mail.example.com, password) in Smtp Client
• You can assign the port of MTA on the host machine to one other than 25 (postfix how-to)
• Read the reference below to find out how to generate domain keys and add public key to the domain's DNS records

• Postfix SASL Howto
• How To Install and Configure DKIM with Postfix on Debian Wheezy
• TBD