When you set up a new Microsoft Exchange 2003 Server You get the following default SMPT Banner

220 internal.domain.com Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959 ready at  Thu, 20 Sep 2007 20:00:00 –0500

To change this you need to do two things:

Change the FQDN address in Exchange System Manager

1. Open Exchange System Manager.

2. Right-click YourServerProtocolsSMTPDefault SMTP Virtual Server (or your SMTP virtual server) and select Properties.

3. On the Delivery tab, click Advanced…

4. Under Fully-qualified domain name: enter the name you want to broadcast to the world.

Change the banner message

goto the folder Drive:InetpubAdminscripts and execute this:

cscript adsutil.vbs set smtpsvc/vsi number/connectresponse “Your Text”. Thos Changes the “Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959 ready at” to “Your Text”

The vsinumber is usually 1 (the number of your SMTP host).

Links

http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=2164469&SiteID=17
http://support.microsoft.com/kb/836564