Blacklist Reply-To Email Addresses

Please create a feature that will allow me to blacklist an email based on the "Reply-To" address. The feature would allow a blacklist choice of "From", "Reply-To", or "Both".

I have been dealing with this for years. Advertising Spammers that every day have a new "From:" address, but the spam always has the same "Reply-To" address (i.e. contactardados@gmail.com). SPAM Assassin is catching these, but I have no way of blacklisting the source. Approximate 30% of my blacklist entries contain "Reply-To: contactardados@gmail.com."

If I can blacklist based on the "Reply-To" address, I don't have to keep blacklisting all the bogus "From:" email addresses from the same person.