Thanks for your interest, i don't receive any error message, simply i don't receive any email (now i have the same problem with thunderbird). When i put off the mail protection in avast i receive all the message in server (checked and not checked by any client) it's look like a reset of the pop3 counter.
To be more clear:
My other clients are blackberry smartphone, my mail server use dovecot, if i don't leave the mail on server it's ok (but my blackberry doesn't receive any mail, of course).
Something about the deploy,
ok the distribution by email but why the clients appear disconnected in the console and i found a lot of error of unauthorized access to server (avast)?
Regards,
Luigi