All, Has anyone been successful in implementing client based authentication with the iPhone and Exchange 2003 (or 2007 for that matter)? Our current implementation requires Windows Mobile devices to obtain a client certificate on the users behalf and then upload it to the phone. Our exchange server then requires the device to present the client certificate before letting them in. This is working on the Windows Mobile side, but is not working on the iPhone side. I've uploaded the client certificate for our test user to my phone and the exchange server (OWA) is displaying the HTTP Error 403.7 - Forbidden: SSL client certificate is required message when I fire up the mail client (also configured to match the email@example.com values in the client certificate). Has anyone had any success in getting this to work, or does anyone have a contact at Apple whom we can work with to resolve this problem? Thanks!