After a migration from Exchange 2007 to 2010. The Exchange integration was broken with Sage CRM 7.1
After many hours of research, even if you recreate everything from scratch according to the Sage documentation, *User, Exchange User Rights, WebServices Testing … reinstallation of CRM, manually edit the integration nothing was working.
To have this re-enable properly, Go to :
Administration -> System behavior -> Turn OFF the option : Use exchange Server Integration.
Administration -> System behavior -> Turn ON the option : Use exchange Server Integration.
Go to your Exchange Integration, reenter your information according to the Sage CRM documentation and your good to go.
Thanks to Sage Technical Support for not knowing this information ! This gave me an headache for couple of hours.