I was asked this by a university in Phoenix. Here is what I found from our Exchange product team:
Prerequisites to make pattern matching work well:
You need Exchange 2007 Sp1 with Rollup10 or Exchange 2007 Sp2 or Exchange 2010
How do I create a sample rule?
In Exchange Command Shell type:
PS] D:\Users\Administrator\Desktop>New-TransportRule testrule -SubjectOrBodyMatchesPatterns "\d\d\d-\d\d-\d\d\d\d\s|$"
The result of the rule firing is:
Asdkljf 349863-43-3454 fg
Not triggered – good
Asdf 636-23-394867987 fgh
Asdfa asdfa 234-23-2345 rfy
Triggered - good
Not triggered- good
More on transport rules here.