Our company had 4 domains whose emails and DNS were hosted by one company, and then we moved the email and DNS hosting for 3 of the 4 domains to a new company. Now, the 3 domains that were moved can't send or receive emails to and from the one domain still left on the old server. All other email functions work fine for all 4 domains. There are no bouncebacks, error messages, or emails stuck in queue, and no evidence of these missing emails hitting the new servers.

The new hosting company confirms that everything is fine on their end, and assures me that it's most likely an old zone file still remaining on the old nameserver, and so the emails sent from the old host is routed to what it believes is still the authoritative nameserver. Because the old zone file's MX records still contain the old resource, the requests never leave the old nameserver to go online to do a fresh search for the real (new) authoritative nameserver. The compounding problem is that the old company is rather inept and doesn't seem to have the technical expertise to identify the problem, much less fix it. (I know, I know.)

Is the problem truly that this old zone file just needs to be deleted from the old company's nameserver? If so, what's the best way for me to describe this to them? If not, what do you think could be the issue? Any help is much appreciated. I'm not in IT, so all this is new to me. I know it seems weird for me (the client) to have to do this legwork, but I just want to get this resolved.

Here's what I've done:

1. Ran dig to verify that the old server's MX records still point to the old authoritative server, instead of going online to do a fresh search:

   ~$ dig @old.nameserver.com domainthatwasmoved.com mx

   ; <<>> DiG 9.6.0-APPLE-P2 <<>> @old.nameserver.com domainThatWasMoved.com mx ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61227 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

   ;; QUESTION SECTION: ;domainthatwasmoved.com. IN MX

   ;; ANSWER SECTION: domainthatwasmoved.com. 3600 IN MX 10 mail.oldmailserver.com.

   ;; ADDITIONAL SECTION: mail.oldmailserver.com. 3600 IN A 65.198.191.5

   ;; Query time: 29 msec ;; SERVER: 65.198.191.5#53(65.198.191.5) ;; WHEN: Sun Dec 26 16:59:22 2010 ;; MSG SIZE rcvd: 88

2. Ran dig to try to see where the new hosting company's servers look when emails are sent from the 3 domains that were moved, and got refused:

   ~$ dig @new.nameserver.net domainStillAtOldHost.com mx

   ; <<>> DiG 9.6.0-APPLE-P2 <<>> @new.nameserver.net domainStillAtOldHost.com mx ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 31599 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; WARNING: recursion requested but not available

   ;; QUESTION SECTION: ;domainStillAtOldHost.com. IN MX

   ;; Query time: 31 msec ;; SERVER: 216.201.128.10#53(216.201.128.10) ;; WHEN: Sun Dec 26 17:00:14 2010 ;; MSG SIZE rcvd: 34