# telnet localhost 110 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. +OK Dovecot ready. user systemman2 +OK pass 123456 -ERR Internal login failure. Refer to server log for more information.
# tail maillog Jul 11 00:52:15 zhengmk dovecot: Dovecot v1.0.7 starting up Jul 11 00:52:32 zhengmk dovecot: auth(default): userdb(systemman,::ffff:127.0.0.1): user not found from userdb Jul 11 00:52:32 zhengmk dovecot: pop3-login: Internal login failure: user=<systemman>, method=PLAIN, rip=::ffff:127.0.0.1, lip=::ffff:127.0.0.1, secured Jul 11 00:53:57 zhengmk dovecot: auth(default): userdb(systemman2,::ffff:127.0.0.1): user not found from userdb Jul 11 00:53:57 zhengmk dovecot: pop3-login: Internal login failure: user=<systemman2>, method=PLAIN, rip=::ffff:127.0.0.1, lip=::ffff:127.0.0.1, secured