[Mimedefang] Detecting S/MIME messages and changing processing

[Paul Murphy]

Hi,

I have both incoming and outgoing encrypted/signed mail which is currently being
processed through MimeDefang and SpamAssassin, but the encrypted messages are
being changed by the addition of header lines, which makes the message fail
signature verification.

I'd like to be able to identify encrypted messages early in the process, and
then allow them through unchanged in either direction.  Is there an easy way to
do this?  Presumably we can check for the existence of a "smime.p7m" attachment,
or one of the header lines:

Content-Type: application/pkcs7-mime;
        name="smime.p7m";
        smime-type=signed-data
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
        filename="smime.p7m"

Additionally, I'd like to implement a block for selected domains, which ensures
that only encrypted messages can be sent to them - any ideas on how to achieve
this?

Best Wishes,

Paul.
__________________________________________________
Paul Murphy
Head of Informatics
Ionix Pharmaceuticals Ltd
418 Science Park, Cambridge, CB4 0PA

Tel. 01223 433741
Fax. 01223 433788


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