As you stated, the group policy objects for Outlook allows you to control the creation but not the viewing. If you are intent on not allow any S/MIME certificates, which are used for encrypting and digitally signing e-mail, you can actually configure your information stores in Exchange so they will not be able store S/MIME; this will also prevent the delivery of signed and encrypted items.
- Using the Exchange System Manager, navigate to the mailbox store that has your user mail on it.
- Now go to the properties page for the mailbox store.
- On the General tab, de-select the checkbox "Clients support S/MIME signatures."
This option was designed to allow compatibility for legacy clients but will have the affect that you are after. On the downside a non-delivery report will be returned to the originator of the encrypted or digitally signed message.
In my humble opinion, though, this is not to be done for security reasons. If you are doing this because your antivirus software doesn't support scanning encrypted e-mail, you should look for one that does, or simply look for one that uses the latest VSAPI (2.5 with Exchange 2003) where S/MIME scanning is supported natively.
Do you have comments on this Ask the Expert Q&A? Let us know.
Dig Deeper on Outlook management
Related Q&A from Richard Luckett
Some folders in a mailbox on Exchange Server 2013 are not showing up on the folder list in the OWA virtual directory but do appear in other views. Continue Reading
We have a Client Access Server and Mailbox Server on Exchange 2013 and we want to install an Edge Transport role on another machine. I joined the ... Continue Reading
How can I enable Outlook Anywhere to allow internal use for all users and external use for only some users in Exchange 2013? Continue Reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.