a Microsoft Exchange Server computer that acts as the endpoint of a connection between two sites and is responsible for routing messages through that connection

a routing server that accepts mail from another server and then distributes the mail to the next server in the route

a server in the local site that takes care of all the message traffic to the remote site

a virtual SMTP server, which is used by an SMTP connector

Server that handles directory replication between sites. Automatically updates other servers within a site.

A Cisco Unity networking term. In installations with multiple Cisco Unity servers networked together, only one Cisco Unity server in the network needs to be configured for AMIS, Bridge, or VPIM networking - the server acts as the "bridgehead" server for the other Cisco Unity servers in the network.

bridgehead server - A computer that connects servers using the same communications protocols so information can be passed from one server to another. In Exchange Server 2003 and Exchange 2000 Server, a bridgehead server is a connection point from a routing group to another routing group, remote system, or other external system.

A Microsoft Exchange Server computer that acts as an endpoint of a connection between two Exchange sites. It is responsible for routing messages through the site connection.