[Dovecot] How to log login errors?

Hi! I used "auth_debug=yes" and "auth_debug_passwords=yes". But I only see connects and disconnects: Apr 11 09:17:43 dovecot: POP3(info@xxxx.xx): Disconnected: Logged out top=0/0, retr=0/0, del=0/0, size=0 Apr 11 09:17:43 dovecot: POP3(info@xxxx.xx): Disconnected: Logged out top=0/0, retr=0/0, del=0/0, size=0 Apr 11 09:18:11 dovecot: pop3-login: Login: user=pop-test@xxxx.xx, method=PLAIN, rip=80.146.3.204, lip=87.106.66.95