Question : claims to be invalid hostname

When I verify my DNS on www.dnsstuff.com, I obtain for my server Exchange (Exchange 2003) :

Mail server host name in greeting

WARNING: One or more of your mailservers is claiming to be a host other than what it really is (the SMTP greeting should be a 3-digit code, followed by a space or a dash, then the host name). This probably won't cause any harm, but is a technical violation of RFC821 4.3 (and RFC2821 4.3.1). Note that the hostname given in the SMTP greeting should have an A record pointing back to the same server.

mail.galilee.be claims to be invalid hostname 'SMTP':
   220 SMTP service ready  

In my Virtual Server>Properties>Delivery>Advanced, I have as Fully-qualified domain name: mail.galilee.be

What can I do ?
Thanks

Thierry

Answer : claims to be invalid hostname

That message looks like it is from the Symantec Firewall, which is a proxying SMTP firewall.  It also re-writes the banner.  When Cisco Mailguard is turned on it will not re-write the banner completely, but will **** out any unneeded information.