[histry]

Fought this in my own exchange 2003 server. Not only does the certificate have to be installed in the IIS on the exchange server, the certificate needs to be from a trusted authority, if you use a self-signed certificate then you have to go through the trouble others here have described of installing the certificate on each device.

If no one else is using the activesync on the exchange, it is entirely possible that he has never set it up. I know that when I started using it I had to go through more hoops to get it to work. You run into troubles when you are using Forms based authentication and the such. Major hassle, but well worth it when it's finally setup correctly.

Exchange 2007 is a breeze.