On Fri, 2010-10-22 at 12:13 +0100, Terry wrote: > Must be a configuration error some where just not sure if it is the clients end our mail server or the Barracuda system
That's someone using a Barracuda appliance with header inspection turned
on. It iterates over all the Received: headers and matches all IP
addresses against the BRBL.
You (well, your customer) has a number of options:
1. Contact the remote site and get them to turn off that feature;
2. Get the offending address removed from the BRBL after dealing with
the issues which got it there;
3. Mask that IP address in the outgoing Received: headers (not
recommended).