Hi Venkadesh,
Hopefully you have received your answer by now. If you have gotten it working, please update the discussion with the solution and mark your question answered.
If you haven't gotten it yet and are still interested - this is something your Basis team needs to set up. They just need to tell you what the address is, then you need to make the settings in SO50, and write the code for the exit to process the inbound email.
I'm only here because we haven't used this feature in a long time and I am about to propose it on a newer SAP system, and wanted to make sure no one was pointing to a newer solution to processing inbound emails. Glad to see it is still in use. 
~ Margaret