Recently I was asked a scenario by my friend on Exchange 2010 in regards to email routing on Exchange 2010.
Further we concluded there is no feature by default but customizing/installing separate transport agent on the server is possible to achieve the requirement.
The requirement was pretty simple(you may find it rarely @any org.) in an Exchange organization there would more than one accepted domain and each SMTP domain should use different smart host server to route emails outside the organization.
Attached is the RoutingRuleAgent document which will help you to achieve the solution and I managed to test in my LAB and sharing the same which contains below topics.
- Installing Transport Rule Agent on Exchange 2010 Server
- Configuring & Enabling Transport Rule Agent on Exchange 2010
- Creating and configuring send connectors
- Creating Transport Rule to work with send connector to achieve the requirement.
- Verifying the event logs instead of testing mail flow to check the installed transport agent was used with transport rule. (Mail flow was successful in my LAB )