docker-postfix

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

Requirement

• Docker 1.0

Installation

1. Build image

   $ sudo docker pull stempler/postfix

Usage

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 stempler/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. Note that the image assumes mail as the name of the selector of the domain key.

   $ 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 stempler/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 stempler/postfix

Additional configuration options

Mail forwarding

To enable simple mail forwarding for the whole mail domain to an external address, use the mail_forward_to environment variable, for example:

-e [email protected]

Note

• Login credential should be set to ([email protected], 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

Reference

• Postfix SASL Howto
• How To Install and Configure DKIM with Postfix on Debian Wheezy
• Forward every mail to an external address
• Versatile Postfix Mail Server Docker Image