Mail Delivery with POP3

If you want to use POP3(S), you have to add the ports 110 and/or 995 (TLS secured) and the environment variable ENABLE_POP3 to your docker-compose.yml:

mail:
  ports:
    - "25:25"
    - "143:143"
    - "587:587"
    - "993:993"
    - "110:110"
    - "995:995" 
  environment:
    - ENABLE_POP3=1