My logwatch daily email keeps getting flooded with lots or unmatched entries which all look legitimate like this;
 **Unmatched Entries**
dovecot: service=imap, 
[email protected], ip=[51.51.51.51]. Logged out rcvd=297, sent=1103: 1 Time(s)
...
  dovecot: service=lda, 
[email protected], ip=[]...