Hi All, I'm just wanting to check that my understanding of the settings is correct as my web searches are finding a lot of dated information. If I want a Centos 6 sendmail system act as the secondary MX for domain bbbbb.co.uk do I just add a Connect:bbbbb.co.uk RELAY statement into /etc/mail/access and restart sendmail Obviously I have the DNS MX records for the domain are already established. I've been getting "/config error/: /mail loops back to me/ " errors. I think I may be stumbling into a variant of cname problem where the hostname as far as the sendmail machine is concerned is aaaaa.com but the DNS setting for the secondary MX is smtp1.bbbbb.co.uk. They both resolve to the same IP but when sendmail looks up the MX records for bbbbb.co.uk it will find smtp.bbbbb.co.uk and smtp1.bbbbb.co.uk listed and it may relay the mail off to smtp1.bbbbb.co.uk without recognising that aaaaa.com = smtp1.bbbbb.co.uk. Am I on the right track here, as I then just need to change the secondary MX setting in DNS to aaaaa.com? Many thanks Ken -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.