Exchange 2013 has the ability to perform as a voice mail system and enables Outlook as the unified inbox to see e-mail, faxes, and voicemail. This capability is called Unified Messaging. In fact, many enterprises are using Exchange as their voicemail system.
One of the key synergies between Lync and Exchange is the Unified Messaging integration. Lync 2013 integrates with Exchange 2013 and can leverage Exchange as the voicemail platform.
In this post, I work through the steps of integrating the Lync 2013 and Exchange 2013 Unified Messaging.
Here is are my step by step notes for establishing this integration: Integrating Lync 2013 with Exchange Unified Messaging