Hey Tamil
The recepient address would be the place where you want the inbound emails to go please check with your client they should be able to provide you that ..
And that email should be SMTP complaint .
Apart from the link which Laurent has mentioned
You may also want to check the below link
it has all the details on how you could setup an email for inbound processing..
Please check and let me know if it helps
| http://wiki.scn.sap.com/wiki/display/SRM/Offline+approval+-+general+configuration |
Regards
vinita