Hi Ranjit,
Verify your steps with the article, it might indicate what you have missed.
http://msdn.microsoft.com/en-us/library/ee782548.aspx
Also go through this if you still cant find any clue: http://blogs.msdn.com/b/mohits/archive/2010/05/29/integration-of-project-server-2010-and-exchange-2010-2007.aspx
Let me know if it helps.
| Khurram Jamshed | Follow my blog about Enterprise Project Management Solution | http://khurramjamshed.blogspot.com |