[rt-users] email filter that sets ticket via subject lookup?

[Robert Eden]

Howdy All.

We work with a vendor and store the vendor's ticket # in a custom field.

We'd like to be able to add a comment to the RT ticket by "cc"ing  RT on 
vendor email. The subject of the message contains the vendor ticket 
number, and I'll determine the RT # via a search.

I'm trying to figure out the best way to do this. The "Right" method 
appears to be a custom  RT::Interface::Email module, but the only "hook" 
appears to be GetCurrentUser and there's no way to set ticket number or 
modify the message.   I looked at the code and don't see a 
"GetCurrentTicket" callback.   Are the  RT::Interface::Email modules 
only good for authentication?

Another method is to replace the  rt-mailgate script with one of my 
own.   This seems like an "excessive" hack into RT internals.  Is there 
a more official way?

Robert