[Dovecot] Strange log entry???

[Bill Landry]

Although everything appears to be working fine, I see the following entry in 
my log file each time someone logs on via the IMAPS service (all other 
services are disables: POP, IMAP, etc.):

==========
Sep  6 02:57:00 mgw1 dovecot: Logins with login process UID xxxx (user 
someone at example.com) not permitted (see login_user in config file).
==========

Any idea what this log entry means and is there a config setting I need to 
adjust to stop these log entries (Dovecot version 1.0.rc7)?

Thanks,

Bill