Using rules for "Remove These Headers"

[Dave Jones]

I need to remove read receipt headers from email coming in from the
Internet.  There are 4 SMTP proxy firewalls (172.16.21.10,
172.16.21.11, 172.16.11.10, 172.16.11.11) in front of the MailScanner
servers that show up in the Received: headers.

Received: from server.blahblah.com (firewall.blahblah.com [172.16.11.11])
     by sendmail.blahblah.com (8.13.8/8.13.8) with ESMTP id o5AHZkoM025256
     for <someone at somedomain.com>; Thu, 10 Jun 2010 12:35:46 -0500

MailScanner.conf (4.78.17)
======================
Remove These Headers = %rules-dir%/remove-these-headers.rules

remove-these-headers.rules
======================
From:           /172\.16\.[12]1\.1[10]/
Disposition-Notification-To: X-Mozilla-Status: X-Mozilla-Status2:
FromOrTo:       default         X-Mozilla-Status: X-Mozilla-Status2:

I have tried many combinations from the MailScanner Wiki ruleset
examples but the header gets through.

Does the "From:" in rulesets cover the from email address and any
Received: headers too?  The wiki seems to show that but I am not able
to remove the header no matter what I use in the second field.

Dave