homeserver/docker-compose/mail-relay/docker-compose.yml.j2

version: '3.3'
services:
  postfix:
    image: "registry.mgrote.net/postfix:v1.1.192"
    container_name: mail-relay
    restart: always
    ports:
        - 1025:25
    environment:
      SMTP_SERVER: smtp.strato.de
      SMTP_USERNAME: info@mgrote.net
      SMTP_PASSWORD: "{{ lookup('keepass', 'strato_smtp_password', 'password') }}"
      SERVER_HOSTNAME: mgrote.net
      # DEBUG: "yes" # as string not boolean
      ALWAYS_ADD_MISSING_HEADERS: "no" # as string not boolean
      # LOG_SUBJECT: "yes" # as string not boolean
      INET_PROTOCOL: ipv4
      SMTP_GENERIC_MAP: |
        /^From:.*nobody@lldap/ REPLACE From: lldap@mgrote.net
        # "/.*/ info@mgrote.net" # deactivated; dont overwrite sender
    networks:
      - mail-relay
    healthcheck:
      test: ["CMD", "sh", "-c", "echo 'EHLO localhost' | nc -w 1 127.0.0.1 25 | grep -q '220 '"]
      interval: 30s
      timeout: 10s
      retries: 3

######## Networks ########
networks:
  mail-relay:
    external: true