S,
There is a way to do this and it is by creating a Custom Data Identifier that looks for email addresses. This will then give you capability of doing a unique match count.
Just take the REGEX you have and create a NEW custom DI for emails. Then you can modify the policy to look for that new custom DI.
**** Keep in mind that the DI uses a different variat of REGEX and you will most probably need to change the REGEX you use in the custom DI.
Try this.. I have not tested it in the DI section:
\b[A-Z0-9._%-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b
Please call solved if possible..
Ronak