Digital Certificate "There are problems with the signature"

Giganews Newsgroups
Subject: Digital Certificate "There are problems with the signature"
Posted by:  pretzel (pretz…
Date: Tue, 5 Sep 2006

Dear All,

We are testing out Digital Certificates as a prelude to Secure Messaging
with some of our Clients.

We obtained individual certificates for ourselves (as there is not many of
us) but started our Client on a Business account with a CA.

After setting up one of their users we notice that most times their email is
fine, but other times instead of the usual "rosette" there is a red line and
the statement "There are problems with the signature.  Click the signature
button for details."

The message in the Security Properties is "Error: The message contents may
have been altered. Signed by sa@<client domain here>.com using RSA/SHA1 at
15:05:47 16/08/2006."

As we use an external mail filter (so all our mail is scanned in transit) we
believe that the scanning by our mail filter is causing the Digital
Certificate to detect a modification (or attempt) and hence the error.

My questions are:

1) Is the above assumption correct, and this is normal?

2) Is there anything that can be done to elimiate this (if caused by an
external mail scanner perhaps not)

3)If we move to Secure Messaging where the email is encrypted and hence
cannot be scanned by our mail filter, should I presume that the above error
will not appear and that all will be OK (at least as much as  it should be)?