MX lists

[Marc Redmile-Gordon]

Hello again,

I hope you can help me get my head above water...

Before I tie up some other DNS & Mail issues I have to sort out trouble with
an "MXentry"
Mails sent to us are being bounced back to the sender like this:

-----Original Message-----
From: Mail Delivery Subsystem [mailto:MAILER-DAEMON at host.ourdomain.com ]
Sent: Monday, November 08, 1999 10:46
To: postmaster; sender at rhbnc.ac.uk
Subject: Returned mail: Local configuration error

  The original message was received at Mon, 8 Nov 1999 10:45:33 GMT from
X.rhbnc.ac.uk

----- The following addresses had permanent fatal errors -----
<mailaddress at ourdomain.com>

----- Transcript of session follows -----
554 MX list for carsplus.co.uk. points back to mailserver.ourdomain.com
554 <mailaddress at ourdomain.com>... Local configuration error

I have removed a masquerading entry in sendmail.cf for "mail.carsplus.co.uk"
I don't think we need ANY reference to this server ( it used to be a pop
account holder but now we just use sendmail and have things routed directly
to us )

So, mail sent to X at carsplus.co.uk is pointed to X at ourdomian.com - I don't
see the problem ?  ( I have been told by various people that there is no
problem receiving mail at domain A addressed to people at domain B simply by
having an mxpoint from B to A)

( The mail server is also a dns server running named on SCO 505. )

Where am I going wrong ?

Thanks,
Marc.