Denis Croombs wrote: > > Denis Croombs wrote: > Sorry, I used mail.server.co.uk as an example, it is happening on approx 10 > or so servers. Don't do that. Use one of the reserved domains for documentation (example.com/org/net) or use the *real* domains you are having issues with. Looks like a sendmail > 8.13.6 issue (at least that what a quick search on the net reveals). Can you reproduce those errors while talking to the other side? If so: Turn up logging in your configuration and run a tcpdump/wireshark to look at the packets going over the network. Cheers, Ralph -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available URL: <http://lists.centos.org/pipermail/centos/attachments/20080126/8bea1b12/attachment-0004.sig>