Statistics for "Deny Mail from domains"?

I have implemented anti spam rules and I am using the Deny Mail from Domains functions.

With the anti spam rules, I move the mails to a database so that at the end of each month, I can say that X thousand E-Mails were prevented from being delivered and I have an audit trail.

Is it possible to easy identify the number of domains that were rejected and is there an audit trail retained anywhere?

Thank you.