error connection dropped by imap server. query capability

Was getting the error for squirrel mail on cpanel server

On Investigating could see issue was in Dovecot

Below is the fix I used

It’s possible that this can be rectified by increasing “Maximum Size of a Mail Process (MB)” under
Main >> Service Configuration >> Mailserver Configuration in WHM.

Once I did it the squirrel mail start working like a charm 🙂