Exchange Server 2010 Standard and Enterprise Edition differences

Standard Edition supports 5 databases per server.

Enterprise Edition supports 100 databases per server.

Valid product key can be used to move from Exchange Evaluation version (Trial Edition) to Exchange Server 2010 standard or Enterprise Edition.

Trial edition does not expire even after 120 days and no loss of functionality will occur after expiry date, so that we can use it in our labs, for testing or trainings and for other non-production purposes.

We cannot use Product key to downgrade the Exchange editions, like to downgrade from Enterprise Edition to Standard Edition. This rule also applies to revert to the Trial Edition.