[CentOS] Centos 6 Sendmail backup MX Config

Fri Feb 13 15:57:50 UTC 2015
Ken Smith <kens at kensnet.org>

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.