Hub Transport Server Role

The function of  Hub transport server role is to intelligently route messages within an Exchange Server 2010 environment. By default, SMTP transport is very inefficient at routing messages to multiple recipients because it takes a message and sends multiple copies throughout an organization.

The Hub Transport server takes a message destined to multiple recipients, identifies the most efficient route to send the message, and keeps the message intact for multiple recipients to the most appropriate endpoint. So, if all of the recipients are on a single server in a remote location, only one copy of the 5-MB message is transmitted to the remote server. At that server, the message is then broken apart with a copy of the message dropped into each of the recipient’s mailboxes at the endpoint.

Policies can be configured in Exchange Server 2010 so that after a message is filtered for spam and viruses, the message goes to the policy server to be assessed whether the message meets or fits into any regulated message policy, and appropriate actions are taken. The same is true for outbound messages; the messages go to the policy server, the content of the message is analyzed, and if the message is determined to meet specific message policy criteria, the message can be routed unchanged, or the message can be held or modified based on the policy.