Recipient address rejected on domain after moving to Cloudflare

Hi all,

I moved the DNS of a domain to Cloudflare and after a day or so I delete the local dns entry from the master and slave DNS.
I got an email from that domain today and tried to reply back and getting the following error:

reject: RCPT from controlpanel.mydomain.com[myip]: 450 4.1.2 <[email protected]>: Recipient address rejected: Domain not found; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<webmail.mydomain.com>

Of course the domain is under email as I haven't changed anything apart from the DNS part.

Any help is very much appreciated.

 

ok this is very strange.
I cannot lookup the domain at all from within the server:

Code:

stelios@controlpanel:~$ nslookup mydomain.com
;; Got SERVFAIL reply from 8.8.8.8, trying next server
Server:        8.8.4.4
Address:    8.8.4.4#53

** server can't find mydomain.com: SERVFAIL

Of course if I run a nslookup from any other server it works fine.
I even changed the DNS under resolv.conf with Google's just to check and same error.

Any idea what is happening?

 

Even if I add 1.1.1.1 which is Cloudflare IP it does not resolve that domain. It is only that domain that has the problem; there are many more in Cloudflare and all are able to resolve.

 

Update. The problem somehow relies into ISPConfig for that domain. I got on this multi server setup a few servers on a different location and no matter where the server is none can resolve that domain. All the rest are working fine.
Any idea how to troubleshoot this?

 

@till I tried many different DNS and all return the same. It is like ISPConfig is trying to resolve that domain from internal DNS.
Any other site resolves fine, it is only that domain that doesn't work and from anywhere outside the ISPConfig servers it resolves and work fine.

 

How do you explain that same DNS (google's or whatever) works fine from any PC/server outside ISPConfig?

 

ok found the problem, it was with the DNSSEC, I've disabled it and works fine.