Hi all - this questions isn't directly related to Zimbra at all, but we are in the process of evaluating mobile devices using activesync with our Zimbra system, and have hit a bit of a roadblock.

We want to have our Activsync users authenticated at out external web proxy using personal user certificates (or some other type of 2-factor authentication) - just using a login and password isn't sufficient. We don't allow password authentication alone for remote access to our intranet, so why would we allow it to our mail server via a mobile device?

We are currently trialling the Nokia E65 and although it has a certificate store there doesn't appear to be any way to make either its web browser or Mail4Exchange client use a certificate to authenticate with.

And I can't find any other mobile devices which clearly say they do support that type of authentication.

Does anyone out there have any experience with trying to beef up the security for Zimbra Mobile users using signed user certificates? Or am I just expecting too much from a cell phone?

Any info appreciated.