Where the data comes from

All of it is public in DNS

The Domain Name System is a public directory. It could not work any other way: every mail server in the world has to be able to look up where mail for your domain belongs, and every browser has to find out which server delivers your website. Your domain's nameservers hand that information to anyone who asks. No proof of anything is required.

We ask exactly like everyone else. What gets shown here is visible to anyone who opens a command line or calls up one of the many DNS tools on the web. The only new thing about this page is the translation: the same records, but in plain words and with a verdict attached.

None of it gets stored

Enter a domain and our server asks its nameservers that same moment, and depending on the question, calls up the website. The result then sits in a cache for at most five minutes, so that a second lookup does not fire off new requests to other people's nameservers. After that it is gone.

We keep no list of checked domains, and there is no history either. What your own browser remembers, the last domain you checked and your saved list, is covered under Privacy.

Hiding it is not something we can do

This is where most of the messages to us come from. Somebody finds their provider or their mail server here, would like the entry to disappear, and writes to us about it. We cannot, and nobody else could either.

All we show is what your own nameservers tell anyone who asks, entirely of their own accord. If we hid it here, it would still be in every other DNS tool, in every command line and at every mail server delivering something to you. A page that declines to show a public record does not make that record private.

To change what is visible here, change the records themselves. Where that happens is what every check tells you under Where do I change this?

What you will not find here

The contents of your email, your credentials, files on your server: none of that is in DNS. So this tool sees none of it either. What gets checked is only the records your domain publishes and the answer your website gives to a perfectly ordinary request.