Can't recieve S/MIME signed email.

I recently set up S/MIME on my computer so I can sign and encrypt email. I am able to send signed email fine. However, I cannot receive signed email. I am running Outlook 2003 with Gmail as my mail host. When I receive a signed email it has an attachment “smime.p7s”. How do I verify the smime.p7s signature? I thought this was supposed to be automatically done by Outlook. The other party and myself are both using free certificates from Comodo. Additionally, the other party uses Thunderbird and it automatically verifies my signature when I send them a signed email.

Here is a screenshot of how a signed message looks in Thunderbird. When I click on the little pen that is circled in red the pop up shows the description of the signature and says that it is correct. Now contrast that to the screen capture Outlook that shows an attachment.

[attachment deleted by admin]


I have just tested this by sending from Outlook to Thunderbird and visa versa.
On both tests I received verifiable digitally signed messages.

I have attached both received emails.
Thunderbird_received.gif is from Outlook to Thunderbird
Outlook_received.gif is from Thunderbird to Outlook

I use Outlook 2003 with Service Pack 2
And, Thunderbird (20060909)

I also checked all the settings that I could think of, and nothing changed how it worked for me.

It might be that you have the file type p7s set to something other than Crypto Shell Extensions.
Check Folder Options, File Types, P7S
Or, that you have loaded something that changed the association.


[attachment deleted by admin]