I think the answer is in your question ? Prefix 188. vs prefix 166. ?
Plus neither 188. or 166. are present in a forward lookup for mailcluster.zen.co.uk ? That's some truly messed up DNS you've got there ? ------- Original Message ------- > > I get: > > root@mail:~# nslookup 188.39.73.166 > > 166.73.39.XXX.in-addr.arpa name = mailcluster.zen.co.uk.
