Terms of use
Last updated 12 October 2026
mailcheck is a free tool. By using it you agree to these terms.
What it is
mailcheck asks public DNS blocklists, reputation services, domain registries and a domain's own servers about an IP address or domain, then shows their answers. A listing is the opinion of the list that published it, not ours. We cannot add, change or remove listings. Removal is always through the list itself.
Acceptable use
- Use it to check addresses and domains you run, or have a good reason to look at.
- No automated or bulk lookups: no scripts, crawlers or integrations hitting
/api/. The lists we ask allow only modest, non-commercial volumes, and bulk use would get everyone's lookups refused. - Do not try to get around the limits, overload the service, or use it to harass anyone.
- Test addresses are for testing your own mail. They are not inboxes: do not use them to sign up for anything or to receive anyone else's mail. Their content is never shown.
Heavy use is slowed down automatically, and someone who keeps going for ten minutes while slowed down is blocked for 24 hours (the Usage page has the numbers). We may also slow down or block any use that breaks these rules, without notice.
Lookups are protected by Cloudflare Turnstile: by using them you also accept Cloudflare's terms for that check.
No warranty
The service is provided as is, without any warranty. Results come from third parties, can be out of date, and can be wrong. Do not rely on mailcheck alone for decisions that matter. As far as the law allows, we are not liable for any loss arising from its use or from its being unavailable.
Changes
We may change these terms or the service at any time. The date above shows the latest version.