Hello Amit,
this can be done from the CLI, there is a command 'oldmessage' which will show you MID, and the message content.
Example:
test.com: oldmessage
MID 1234567: 2 days 21 hours 6 mins 10 secs old
From unknown Sat Mar 09 23:13:28 2013
Received: from localhost by ;
09 Mar 2013 23:13:28 +0530
Message-Id: <9e55@example.com>
Date: 09 Mar 2013 23:13:15 -0600
To: user@test.com
From: "Mail Delivery System" <mail.notification@tcs.com>
Subject: Undeliverable Message
Hope that helps,
Andreas