Here’s a useful command when you’re dealing with Plesk very often. This lists all the account names and their passwords for all the mailboxes in your Plesk Controlpanel.
While you could/should argue it’s unsafe of Plesk to store them in plain text like that, it sure comes in handy when troubleshooting.
# /usr/local/psa/admin/bin/mail_auth_view
Authentication database contents:
+-–-–-–-–-–-–-–-–+-—-+-–-–-–-–-–-—-+
| address |flags| password |
+-–-–-–-–-–-–-–-–+-—-+-–-–-–-–-–-—-+
| user1@geniar.be | | SomethingRandom |
| user2@geniar.be | | SomethingRandom |
| user2@geniar.be | | SomethingRandom |
| user3@geniar.be | | SomethingRandom |
…
So keep that /usr/local/psa/admin/bin/mail_auth_view command in mind!