Delivery Agent Connector is a new type of connector introduced in Exchange 2010 to communicate with foreign systems that doesn’t talk SMTP. It is much better than a foreign connector which also does the same job.
Following are the points in favour of a delivery agent connector.
- It allows queue management of messages.
- No more drop directory.
- Messages can be tracked.
A delivery agent is responsible for working with a delivery agent connector. The third party companies can develop delivery agents and that can be used on 2010 Hub servers.
Exchange 2010 comes with a delivery agent connector by default, Text Messaging Delivery agent Connector and is configured to route messages to the “mobile” address type. Running Get-DeliveryAgentConnector reveals the default connector.
Get-DeliveryAgentConnector | fl brings all the settings of the connector. It has similar parameters like any other connector – address space, cost, source servers, message size etc. The connector can be scoped as well.
By default, all hub servers are added as the source transport servers for the connector. Microsoft recommends using a delivery agent connector wherever possible. A new connector to keep in mind, exclusive to 2010 
Sijay June 14, 2012 at 2:14 pm
I want to know, at what stage during installation does the Text Message Connector installed?
Thank you
Rajith Enchiparambil June 26, 2012 at 2:09 pm
It’s part of the Hub transport role install Sijay. Why?