More headers for whitelisting?

I am doing dccproc for the time being.  Of course by the time an
e-mail makes it to a point where dccproc can use it (i.e. procmail or
other local delivery means) one loses all the envlope information,
save for "Return-Path:" and/or "Delivered-To:" headers if one's MTA is
so gracious.

I am wondering if it would not be useful in whitelisting (at least) to
at least recognize locally more headers.  Personally, I would ideally
like to see Return-Path: and Sender: matching for whitelisting
purposes.

I am a hacker.  If somebody wants to point me to the right place to
hack, I will hack it in.

b.