Hi Gaurav,
Unity Connection 7.x still has access to messages via PCA>Inbox and
can be saved off using the Options>Save as
Messages can also be isolated and recovered via the DRS Message Fisher Tool for Unity Connection
from the great suite of Unity Tools
http://www.ciscounitytools.com/Applications/CxN/DRSMessageFisher/DRSMessageFisher.html
Cheers!
Rob
"And if I should fall behind
Wait for me" - Springsteen