I have this error message for POP3 clients which are using Ms Outlook 2007.
Anybody knows what this means?

2010-08-31 15:51:00,359 INFO [Pop3SSLServer-3436] [ip=xxx.xxx.xxx.xxx;] pop - connected
2010-08-31 15:51:00,402 INFO [Pop3SSLServer-3436] [ip=xxx.xxx.xxx.xxx;] pop - -ERR mechanism not specified (AUTH )
2010-08-31 15:51:00,443 INFO [Pop3SSLServer-3436] [name=user@domain.lt;ip=xxx.xxx.xxx.xxx;] pop - user user@domain.lt authenticated, mechanism=LOGIN [TLS]
2010-08-31 15:51:00,679 INFO [Pop3SSLServer-3436] [name=user@domain.lt;ip=xxx.xxx.xxx.xxx;] pop - quit from client
2010-08-31 15:51:00,679 INFO [Pop3SSLServer-3436] [] ProtocolHandler - Handler exiting normally