Simple Postfix SMTP docker image with SASL and DKIM authentication.
It also includes syslog to enable logging to stdout.
docker run \
-p 25:25 \
-e MYHOSTNAME="mail.example.com" \
-e MYDOMAIN="example.com" \
-e INET_INTERFACE="all" \
-e MYNETWORKS="172.16.0.0/12" \
-e RELAYHOST="[172.16.0.1]" \
-e TZ="Asia/Tokyo" \
-e SASL_USER="test:foobar" \
-e DKIM_KEY="dkim private key include LF" \
actindi/postfix-sender:latest
Create a private key on other host.
opendkim-genkey -b 2048 -d example.com
Set private key to DKIM_KEY, and public key set to DNS.
MYHOSTNAME
: Postfix main.cf 'myhostname' setting. And SASL realm.MYDOMAIN
: Postfix main.cf 'mydomain' setting. And OpenDKIM 'Domain' setting.INET_INTERFACE
: Postfix main.cf 'inet_interface' setting.MYNETWORKS
: Postfix main.cf 'mynetworks' setting.RELAYHOST
: Postfix main.cf 'relayhost' setting.TZ
?: time zone. default is UTC.SASL_USER
?: If use SASL authentication, set 'user:password' format. Only one user.DKIM_KEY
?: If use DKIM authentication, set RSA key.