[cobalt-users] Problem with catchall

["Achieve IT" <info@xxxxxxxxxxxxxx>]

I have setup a catchall email account for a client of mine. I used the
instructions which I found in the archive, ie @www.domain.com . My problem
is that eventhough my client is receiving the emails which are sent to
anybody@xxxxxxxxxx , the sender receives an email from postmaster@xxxxxxxxxx
stating "Delivery to the following recipients failed."

Has anybody come across this before?

Thanks,
Declan.