Exchange Server 2007 Anti-Spam graphical user interface has a tab to allow a list of pre-defined recipients to bypass the content filter (Organization Configuration->Hub Transport->Anti-Spam->Content Filtering), but in this instance we really needed to allow certain internal hosts to bypass the filter too.

Digging around on Microsoft Technet, in particular the Exchange Server Tech Center, we found an article that explained more about the command line interface cmd-let Set-ContentFilterConfig, in particular the these two parameters

• BypassedSenderDomains
• BypassedSenders

So, to bypass a particular sender use :

Set-ContentFilterConfig -BypassedSenders sender@domain.com

And to bypass a whole domain use:

Set-ContentFilterConfig -BypassedSenderDomains domain.com

Both of these settings need to be applied with caution as bypassing anti-spam controls needs careful consideration, it is often best to bypass what you absolutely need rather than blanket allowing domains.

Further Reading

• Microsoft Technet: Set-ContentFilterConfig
• Microsoft Technet: How to Specify Recipient and Sender Exceptions for Content Filtering