avoiding duplicates from separate mailing lists?

I am on two mailing lists that are similar in their nature and come from the
same domain.  Sometimes, however, a person sends the same email to both lists.
Is there a way to have procmail detect this and filter out the second message?

Here's an example: Say the first list receives, procmail sees that it is TO
list1(_at_)domain(_dot_)com and delivers it to lists/list1.  A bit later 
(seconds,
minutes), the second list receives the same message from 
list2(_at_)domain(_dot_)com and
filters it to lists/list2.  I'd like procmail to say "oh, this message to
list2(_at_)domain(_dot_)com is the same as one I filtered to 
list1(_at_)domain(_dot_)com, so I'll
ignore it."

Does that make sense, and is it possible?

JcL

-- 
Justin C. Lloyd               Harris Corporation, ISD     Voice  407/984-5558
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