This script is Copyright (C) 2003-2017 Tenable Network Security, Inc.
An open SMTP relay is running on the remote host.
Nessus has detected that the remote SMTP server is insufficiently
protected against mail relaying. This issue allows any spammer to use
your mail server to send their mail to the world, thus flooding your
network bandwidth and possibly getting your mail server blacklisted.
See also :
Reconfigure your SMTP server so that it cannot be used as an
indiscriminate SMTP relay. Make sure that the server uses appropriate
access controls to limit the extent to which relaying is possible.
Risk factor :
High / CVSS Base Score : 7.8
CVSS Temporal Score : 6.7
Public Exploit Available : true