On Wed, Feb 06, 2008 at 02:52:41PM -0800, Paul B. Henson wrote:
>
> One of my users was recently complaining that all the mail he received that
> was PGP signed had broken signatures. While investigating, he determined
> that the MIME headers of the messages were being altered by our gateway
> resulting in broken signatures.
Are you perhaps using some tool such as MIMEDefang or the Anomy mail
sanitizer on the gateway?
Postfix and Amavisd are both careful not to alter MIME content, but
there are tools which specifically normalize MIME content to defeat
mail scanner evasion logic coming from viruses or malware. Those I
just named are a couple, but I believe some commercial products do this
as well.
It's also possible that an AV product on the user's machine are doing
this, for instance there are AV packages which install a POP or IMAP
proxy on the client machine and filter all incoming mail through it.
These are a few possibilities to check for.
-- Clifton
--
Clifton Royston -- [EMAIL PROTECTED] / [EMAIL PROTECTED]
President - I and I Computing * http://www.iandicomputing.com/
Custom programming, network design, systems and network consulting services
-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
AMaViS-user mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/amavis-user
AMaViS-FAQ:http://www.amavis.org/amavis-faq.php3
AMaViS-HowTos:http://www.amavis.org/howto/
