From: DeskNow Knowledge Base
http://www.desknow.com/kb/

How do I change the greeting banner used for SMTP, POP3, IMAP
http://www.desknow.com/kb/idx/5/156/article/
This article applies to DeskNow 3.2.1 and later

You can change the software type shown in the IMAP, POP3 and SMTP banners. This may help in providing less information to potential intruders.

To change the software type shown in the banner (note - the total banner cannot be customized, as it may have to meet protocol requirements), simply add this line to Mail.cfg:

EmbeddedServer.BannerSoftwareName "My other name"

 

and restart DeskNow.