Fake email domain debugger
“The code never arrived” has three quite different causes, and from the sign-up form they look identical. This tells them apart in a couple of seconds. Paste the whole address — or just the domain — and it checks:
- whether the address itself is written in a form that can work at all;
- whether the domain exists and what its name servers answer;
- whether any mail server accepts mail for it, and whether that is us;
- whether it is a Gmail variant that is really the same mailbox as another;
- what an internationalised domain looks like in the ASCII form forms expect.
Reading the answer
| What you see | What it means | What to do |
|---|---|---|
| Green line at the bottom | The domain points here, and mail will reach us. | Nothing. If messages still do not arrive, the sender is not sending them. |
| Our server is listed, but not first | A record with a smaller priority number is taking all the mail. | Give ours the lowest number, or remove the other records. |
| Two records share the highest priority | The sender picks either one, so mail arrives only some of the time. | Leave a single record at the lowest number. |
| MX records exist, but point elsewhere | The domain is fine; its mail is simply handled by another system. | If the domain is yours, repoint the record to us. |
| No MX record found | Nothing anywhere will accept mail for this domain. | Add a record — the steps are below. |
| No name servers found | The domain is not live on the internet at all. | Usually this means the registration has expired. |
ℹ️
The lookup is made by our server against public DNS at the moment you press the button — there is no queue and no cached verdict from an earlier visit. What you get back is what DNS is saying right now.
What this cannot tell you
One thing deliberately: whether a particular website will accept an address at this domain. That is a policy list on their side, invisible from outside, and no DNS check can see it. If the domain checks out here and a sign-up form still refuses it, the domain is fine and the form is the obstacle — what to do then.
Next steps
- Add your own domain — the exact MX values, and this page to confirm they took.
- Mail stopped arriving — the three answers above, worked through in full.
- The domain is gone — what the registry status means and whether waiting helps.