docker-mailserver/docs/content/config/troubleshooting/debugging.md

..todo.. - Please contribute more to help others debug this package

Invalid username or Password

1. Login Container

docker exec -it <mycontainer> bash

2. Check log files

/var/log/mail could not find any mention of incorrect logins here neither in the dovecot logs

3. Make sure you set your hostname to 'mail' or whatever you specified in your docker-compose.yml file or else your FQDN will be wrong

4. During setup, if you get errors trying to edit files inside of the container, you likely need to install vi:

sudo su

docker exec -it mail apt-get install -y vim