This script is Copyright (C) 2008-2011 Tenable Network Security, Inc.
A mail filtering service is listening on the remote host.
The remote service is a milter, which provides an interface between a
mail transfer agent (MTA) such as sendmail and an application such as
SpamAssassin or ClamAV for filtering messages.
See also :
Limit incoming traffic to this port if desired.
Risk factor :