Debugging
Poste.io try to log as much as possible. There are couple places where you can find valuable logs when debugging:
docker logs --tail=100 mailserver
there should be all information about starting and stopping services./your-data-dir/logs
its essentially copy of /var/log from inner container. There are couple special directories besides standard ones:- admin-app - web administration errors log
- delivery - all logs from email delivery should be logged there
- dmarc - received DMARC reports
- s6 - contains output from supervised services
/your-data-dir/domains/domain.com/username/.dovecot.sieve.log
whenever sieve script fails there should be error logged to this file under user mailbox directory
PRO version
In PRO version you can search through delivery logs at web administration.