[exim] Blocking Email Addresses

I am writing a perl script that creates a list of email addresses that
have not been checked in over 6 months time. I would like exim to
refuse any messages destined for these addresses. How would I make
Exim refuse messages addressed to addresses in a file?

Main reason for this is that most of these addresses are over quotta
and full of SPAM and just generate over quotta bounces.

Matt