walker2022/postfix repository overview

Create postfix container with smtp authentication

# Set multiple user credentials: -e smtp_user=user1:pwd1,user2:pwd2,...,userN:pwdN

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

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

#Set DKIM select: -e dkim_select=dkim

$ sudo docker run -p 587:587 \
		-e maildomain=mail.domain.com -e smtp_user=user:pwd \
		-e dkim_select=dkim \
		-v /path/to/certs:/etc/postfix/certs \
		-v /path/to/dkim.key:/etc/postfix/dkim.key
		--name postfix -d walker2022/postfix

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