Hi Nishanth,
We have implemented custom solution for the same in line of SC offline approval process.
And its working fine in Production environment.
Check this blog for SC:
http://scn.sap.com/docs/DOC-56096
http://wiki.scn.sap.com/wiki/display/SRM/Debugging+hints+for+sending+email+in+offline+approval
Thanks
Ankit Jain