Simon Butler is a brilliant Microsoft Exchange Server MVP ... check out his post on getting BES 4.1 to work with Exchange 2010.

That said, if you're on Exchange 2010 why haven't you upgraded to BES 5.0 yet?

Continuing on with another registry tweak ... here's a way to control whether users can send read receipt messages from their BlackBerry handhelds. Personally, I hate read receipts and would block them at the transport layer, but if you allow them and just want to prevent them from coming a la BlackBerry here's the way to do it.

Taken from the BES 4.1 SP4 Release Notes:

In BlackBerry Enterprise Server Version 4.1 SP4 (and later), you can control whether users can send...