Roundcube emails not showing after migration
A common problem, especially after migrating to a different system (for example from Plesk to cPanel or Cwp) is that sometimes emails do not appear correctly at Roundcube. This happens because the dovecot index files are not correct or have wrong permissions.
To fix this you simple delete all files starting with dovecot* inside the email directory that has the problem.
After this open Roundcube again and the problem should be gone.