Lync and Office 365 - Duplicate Contacts as Recipient Cache

User migrated to Office 365 and still using Lync 2010 client will see the duplicate contacts as Recipient cache in Lync search. Lync 2010 client is pulling duplicate contacts from recipient cache in outlook. The recipient cache seems to be a hidden folder and integrated with Lync search.

The solution to avoid duplicate entries (recipient cache) in the Lync search is to exclude the Recipient Cache contact folder from the Lync search. It can be implemented through the Lync client policy on Lync Server.

Set-CsClientPolicy -Identity Global -ExcludedContactFolders “Recipient Cache”

Change the client policy name as per your requirement.

If your organization is migrated to Office 365 and using Lync 2013 or SfB client, then there is no need to implement this change. As the issues seem to be resolved in the later version.