fetchmail keep showing exit status 5

[herovaxy]

My goal is to sync my emails across different devices.

My company has the email server. I log in on outlook via pop3 and it will download the emails onto my laptop via .pst file. The problem with pop3 is that every email that I sent will be stored locally and my other device won’t even see it.

I previously set my outlook this way:

Incoming Mail
mail.example.com
Port 110

Outgoing mail
Port 1000
Encryption method none

Now, I want to use my UGreen NAS Docker to fetch pop3 emails from my company’s email server and act as a middleman. My laptop will just retrieve the files from my NAS (middleman) instead. But, after few hours set up, I’m seeing errors all day and I honestly don’t know what’s wrong.

compose.yaml:

services:
  mailserver:
    image: ghcr.io/docker-mailserver/docker-mailserver:latest
    container_name: mailserver
    # Provide the FQDN of your mail server here (Your DNS MX record should point to this value)
    hostname: mail.example.com
    ports:
      - "25:25"
      - "465:465"
      - "587:587"
      - "110:110"
      - "993:993"
    volumes:
      - ./docker-data/dms/mail-data/:/var/mail/
      - ./docker-data/dms/mail-state/:/var/mail-state/
      - ./docker-data/dms/mail-logs/:/var/log/mail/
      - ./docker-data/dms/config/:/tmp/docker-mailserver/
      - /etc/localtime:/etc/localtime:ro
    environment:
      - ENABLE_RSPAMD=0
      - ENABLE_POP3=1
      - ENABLE_FETCHMAIL=1
      - FETCHMAIL_POLL=300
      - ENABLE_CLAMAV=0
      - ENABLE_FAIL2BAN=0
    restart: always
    stop_grace_period: 1m
    # Uncomment if using `ENABLE_FAIL2BAN=1`:
    # cap_add:
    #   - NET_ADMIN

docker-data/dms/config/fetchmail.cf:

poll mail.example.com proto pop3
user '[email protected]'
pass 'heropass'
is '[email protected]'
keep

Error message:

WARN exited: fetchmail (exit status 5; not expected)

What did I do wrong?

[casperklein]

Check /var/log/supervisor/fetchmail.log for errors.

If it doesn’t strictly have to be fetchmail, you can also try getmail.