[Mimedefang] PGP signed mail garbled?

[Gary Funck]

I only recently started using and paying attention to
PGP-signed email, and noticed that the PGP mail that
I receive results in the following diagnostic from
Outlook 2000 when the message is opened:
"Contents altered after message was signed"

I don't think the message was actually altered, but
I'm surmizing that MdF disassembled and then reassembled
the message, and that this may have disturbed the
contents of message sufficiently to cause the message's
PGP certificate to know longer match the message.

Have you seen something like this?  Are there tools
that might help further diagnose this problem?  I suppose
that I could cause MdF to save a few original PGP signed
mails into an incoming folder on the mail gateway and
compare them against the delivered mail, but it'll be
a while before I can get to that.

We don't do any of the more aggressive "defanging" types
of operations, but we do allow MdF to disassemble and
reassemble the message, and adding the usual headers.

Any ideas?