[cobalt-users] config error: mail loops back to me (MX problem?)

["Ja" <jjma@xxxxxxxxxxxxxx>]

Having searched through the archives, sendmail faq and asked a few experts
but am come to a dead end. I have setup a raq4 as a primary dns server
hosting a few sites and a raq2 a slave dns server. When I try to send to one
particular site on the raq4r the email bouces back with configuration error
553.

I have checked local-host-names and the site seems to be mentioned in there.
As I am not fully literate with sendmail I would appreciate help, paid or
unpaid.

Thanks

Jonathan