Email "Host unknown" error

Hi Everyone

After using Cloudflare pro plan.

Some of emails are missing.

One of the message is :
Host unknown: non-recoverable

I sent an ticket to Cloudflare support. They said it’s about Cloudflare Spectrum and bypass.

After reading the Cloudflare document. Still no idea about it.

I would like to use our own email provider.

Is there any one who know how to make the correct settings?


Switch all DNS records that are related to email traffic to Unproxied (:grey:) / DNS-only.

Thanks for your reply!

Here is our Cloudflare DNS settings.

It seems in Unproxied / DNS-only.

Am I missing something?

Hope your guide.

Thank you very much.

Your MX record points to your apex name which is :orange. Hostnames that are :orange: will not be reachable by email protocols.

Take a look at this Community Tutorial. It covers how to fix your problem.



Thank you for your reply.

Just check the Tutorial video.

I tired to set the MX record as below:

Is it correct?
(Just test an email. Seems not working)

Hope your guide.


I get the same SMTP banner when I connect to mail or the origin server IP on port 25. You might check with your hosting to verify the IP you are using.

1 Like

Hi Sir

Our mail server IP is

After testing.

We can get yandex mail, aol mail, gmail, yahoo mail…

Only email from Japan can not be received. It seems Email unable to resolve.

Still don’t know where is the problem is.

Hope your guideline.

Our DNS setting:

Big Thanks!

It resolves correctly.

dig +short

DNSSEC is fine.

Most likely cause islocal resolver error… so the sender should confirm with their mail provider. Some mail servers are bad at caching / validating updates to mail servers. The correct values are available in DNS, but a noncompliant resolver may need a ‘kick’ which is a problem with the server, not your DNS.


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