Connect your voice mail system to your telephone network in Exchange Online
After you've deployed all the required telephony equipment for your organization, including your VoIP gateways, IP PBXs, and SIP-enabled PBXs or Microsoft Lync Server, you need to create all the Unified Messaging (UM) components that will enable your telephony devices to communicate with servers in your organization.
The UM components enable the integration of Unified Messaging into your directory structure and your existing telephony infrastructure. Your directory stores all the components and settings for UM. Each UM component is necessary to support Unified Messaging. Some UM components are created to represent a telephony hardware device. Others are created to represent a telephony dial plan for an organization or to support a specific feature of Unified Messaging.
There's a tightly integrated and interconnected relationship between the UM components and the features available in Unified Messaging. To successfully plan and deploy Unified Messaging in your organization, you need to fully understand the relationship between each UM component and the others.
For more information about the UM components, see:
For more information about setting up voice mail for users, see: