We're using CPanel for our DNS server and mail server. We recently created a domain, and configured the nameserver so that the website is on one server (e.g. 192.168.0.1), with the mail server being on a different server (e.g. 192.168.0.2). The problem we're having is that the MX Record is correctly setup to point to the .2 server, yet for some reason some customers trying to send an email to that domain are getting undeliverable bounce backs because they are trying to incorrectly send to the .1 address. When I do an nslookup on the mail domain (our internal network is separate from our ISPs, so we should be the same as any other user), it returns the right value. But when I used an online tool to return the value, it incorrectly returns the web server ip address. One other strange problem is that it appears as though some can send an email directly to the domain, but if they attempt to reply to a message it then is routed incorrectly and bounced back. Anyone have any ideas of what might be happening here? This is driving me crazy, and our customer is having fits and is demanding an immediate resolution. Thanks in advance for your consideration.
Do you have the same mx record for both of the nameserver records ? You have to have same mx record at your parent nameserver and your web server.
I assumed you are trying to send emails from outside sources like yahoo mail, gmail? And it's still an issue? If it's possible, can you post the error domain?