I've set up a new domain on my new server and when testing the DNS I receive 2 warnings that I'm concerned about:

1) Delivery over IPv4 to [email protected] could not be done.

2) Failed to deliver email for SOA RNAME of domain.co.uk (server.domain.co.uk) using [email protected].

Does anybody have any thoughts on how I can resolve these errors. I have a SOA record in place as well as rDNS (as far as I can see in my DNS), but I can't work out why these errors are displayed. The email address is definitely set up and working too.

  • 1
    How have you set everything up? What is the server type? Where is the domain registered? What software or website is giving this error? What action did you take to get the error generated? Is it reproducible?
    – Tim
    Jan 13, 2016 at 21:32
  • I've linked to the errors (dnscheck.pingdom.com/?domain=atomicpenguinclothing.co.uk). The website behind it is running fine and so are the emails, it's just these warnings. The server is running centOS 6 with cPanel. Jan 13, 2016 at 21:35

3 Answers 3


It looks as though the two warnings are related: the second field in your SOA field is server.atomicpenguinclothing.co.uk., meaning that the DNS contact is [email protected]. Does mail to that email address go through?

  • 1
    Yup - that's a valid email address that exists on the server! Jan 13, 2016 at 22:08

It looks like Pingdom are using a really old version of .SE's DNSCheck tool. We removed the test that's failing for you a couple of years ago, for the reason that it's highly unreliable. It gives false negatives or false positives as much as half the time, which makes it worse than useless. It's also not really fixable, since it tries to answer the question "Will mail to this address reach a recipient?", which is both outside the scope of DNS and very ill-defined. So, in short, you can safely ignore this failure.

Or try testing your domain with either .SE's DNSCheck or the newer tool we (together with AFNIC) wrote to replace it, Zonemaster. Both tools are Open Source, written in Perl and available from Github. Zonemaster is also on CPAN. Both tools have command-line versions if you prefer that to web-based services.


It helps when you actually post the domainname rather than link to a tool that explores it.

You SOA record is:

 atomicpenguinclothing.co.uk. IN    SOA ns1.atomicpenguinclothing.co.uk. server.atomicpenguinclothing.co.uk. 2016010704 86400 7200 604800 86400

The field server.atomicpenguinclothing.co.uk. is supposed to be an email address which can be used to contact the DNS administrator, with the first dot . getting replaced by an @. Is that a valid email address?

Because it appears that SMTP port (tcp 25) is not responsive on the MX record atomicpenguinclothing.co.uk.

  • That email address is a valid email address that I have set up. I'll have a look and see if I can open port 25 and see if that fixes any issues. Jan 13, 2016 at 22:08

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