Problem with mail bounces?

[codek]

Hi,

One of my clients is sending mail to people who register on his site.

When they register with an invalid mail address, the bounce comes to me, rather than to the email address the mail was sent from.

Previously, exactly the same code on an ensim server caused the mail to go to the address of the sender, rather than the admin ( me! )

Any ideas? Is this expected behaviour, and is it tuneable? Can't find anything in WHM...

Perhaps i should open a ticket with cpanel on this? Would that be acceptable?

Thanks!
Dan