Domain A registered with Godaddy, authorative DNS is with GoDaddy
Domain B registered with Godaddy, authroative DNS is with Peplink at our office
Domain a has several cname entries remote, ftp, etc that point to domain B. This way if either of our ISP's go down we still have service.
If the peplink goes down, our web page still works since DNS is with Godaddy
rDNS is properly configured on our ISP for remote.domaina.com and SPF is configured for domain a
Issue is with sending mail from our SBS 2008 mail server to craigslist. Research into the problem suggest the mail is being rejected by craiglist because our internal fqdn for the server and its ip address appear in message headers. The resolution seems to be to add a transport rule to remove message headers, but this seems extreme to me.
I've also read that this is customary for every mail server so I doubt that is the problem or else craigslist would be recieving thousands of complaints. Keep in mind I can send mail to msn, aol, google with no problems. So my thought is craiglist must be choking on my cname of remote.domaina.com pointing to remote.domainb.com
My work around is to clear the cname entry and use the hosts in Godaddy usually used for name servers to make an entry for remote. In IP 1 is ISP a and IP 2 is ISP b. My hope is if ISP a goes down the next Ip in the host record will work. As I'm waiting to test this out I though I would see if anyone has a better solution.