А вот эта последовательность выполнена?
Configure users
1. Log on to the Microsoft Exchange Server computer (EXBE01) as a user with Domain Administrator privileges.
2. On the Start menu, point to Programs, point to Administrative Tools, and then click Active Directory Users and Computers.
3. Click View, and then click Advanced Features to enable viewing advanced feature property sheets.
4. In the console tree, click Users, right-click a user in the details pane, and then click Properties.
5. Click the Exchange Advanced tab and click Custom Attributes.
6. Select the first available extensionAttribute. (On a new installation, the first one should be available.) Click Edit.
7. Type CRMEmailEnabled, and click OK.
8. Click OK to close the Exchange Custom Attributes dialog box, and then click OK.
(см.
http://www.microsoft.com/technet/pro.../15_sbsrv.mspx )