Setup two user accounts:
1) dinesh-xyz
2) dinesh-abc
Make sure you have the virtusertable feature setup
(Look for or enter the following into sendmail.mc):
FEATURE(`virtusertable',`hash /etc/yourmailpath/virtusertable')dnl
Create or edit your /etc/yourmailpath/virtusertable file:
Setup the following entries:
dinesh@xyz.com dinesh-xyz
dinesh@abc.com dinesh-abc
Build the db file Sendmail uses for this feature:
makemap hash /etc/yourmailpath/virtusertable.db < /etc/yourmailpath/virtusertable
Reload Sendmail.