This is the message I get:
maillog:
Sep 6 20:58:05 dovecot: imap-login: Login: user=<>, method=DIGEST-MD5, rip=127.0.0.1, lip=127.0.0.1, mpid=592378, secured, session=<l6DOUrUENN/AAAB>
Sep 6 20:58:05 dovecot: service=imap, user=, ip=[127.0.0.1]. Disconnected: Logged out rcvd=512, sent=11322...