Outlook Rich Text Format messages - how to let through?

[Jody Cleveland]

> Yes it's a new filetype/filename block with 4.50.
> 
> I disable it as I find I get too many false positives.

What's the proper way to disable it? 

I tried putting this into filetype.rules.conf:
deny        Transport Neutral Encapsulation Format          Windows
security vulnerability                               No Outlook Rich
Text Format messages due to security hole, use HTML instead

But, they still get blocked. I tried switching that to allow, and they
still get blocked.

- jody