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

How do I turn off antispam?
http://www.desknow.com/kb/idx/4/082/article/

In some circumstances you may want to turn off all antispam measures, for instance if spam filtering for your domain is already provided by an external antispam appliance or service.

Or you may want to turn off just individual antispam measures.

A description of all the different antispam measures available in DeskNow is in the administration manual.

Individual users can turn off spam filtering in the Preferences/Mail/Spam section (DeskNow 3.1 and later).