Requirements

Note: If you do install the de-duplication database, you must do so before installing the Universal Adapter.

The machine that will host the Universal Adapter de‑duplication database must have Microsoft SQL Server 2008 or 2012 installed.
Only one server hosts the de-duplication database. However, multiple Universal Adapters can access the same de-duplication database.
In addition to selecting the De-Duplication Support feature, to use the de‑duplication database you must also configure the DeDuplicate registry value for each mailbox input and follow the database installation instructions below.