/docker-postfix

run postfix with smtp authentication (sasldb) in a docker container

Primary LanguageShellMIT LicenseMIT

docker-postfix

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

Forked from catatnight/postfix to add some more flexibility

  • Allow to choose the certificate (default to the first cert found)
  • mail.log is now displayed inside the container log
  • Increase verbosity
  • Allow to set the smtp restrictions
  • Add a docker-compose file

Requirement

  • Docker 1.0

Installation

  1. Build image

    $ sudo docker pull catatnight/postfix

Usage

  1. Create postfix container with smtp authentication

    $ sudo docker run -p 25:25 \
		-e MAILDOMAIN=mail.example.com -e USERS=user:pwd \
		--name postfix -d catatnight/postfix
# Set multiple user credentials: -e USERS=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 USERS=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 USERS=user:pwd \
		-v /path/to/certs:/etc/postfix/certs \
		--name postfix -d catatnight/postfix

Environment variables

MAILDOMAIN=mail.example.com
MAILSIGNING=example.com # Will sign *@example.com instead of *@mail.example.com
USERS=user1@example.com:password1 user2@example.com:password2 ...
CERTNAME=example.com # lookup for example.com.crt and example.com.key
SMTP_RESTRICTIONS=permit_sasl_authenticated,reject_unauth_destination # SMTP restriction option (see postfix doc)

Docker compose

Edit to suit your needs and run docker-compose up -d --build

Note

  • 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

Reference