Below is a sample maillog using port 587 with None encryption:
Mar 11 06:58:36 server dovecot: pop3-login: Login: user=<
[email protected]>, method=DIGEST-MD5, rip=112.200.103.222, lip=172.31.222.21, mpid=28260, TLS, session=<GO7sjR1nBjdwyGfT>
Mar 11 06:58:36 server dovecot: service=pop3...