Email forwarder checker
Is this a private relay, or a domain that forwards its mail? No signup.
What the answer means
- Private relay
- The domain belongs to a service that gives people private addresses and forwards their mail to a real inbox. The API sets
relay_domainto true for these. - Forwards through a service
- The domain isn't on the relay list, but its MX records point at a forwarding service. That's often someone's own domain, and it's normal. The domain can belong to anyone.
- Not a known forwarder
- It isn't on the list and its mail servers aren't a forwarding service we recognise. It could still forward mail: a server can pass mail on without showing it in DNS.
A relay isn't a throwaway
People use relays to keep their real address private and to shut off an address that gets spam. Someone did sign up, and mail does reach them. So we don't call these disposable, even when an open list does, and we don't mark them risky for it.
You can't catch every relay by domain. iCloud+ and Fastmail masked addresses sit on domains shared with normal mailboxes, so they look like any other address.
The relay list
- aleeas.com
- SimpleLogin. Their page
- simplelogin.co
- SimpleLogin. Their page
- passmail.net
- Proton Pass. Their page
- privaterelay.appleid.com
- Apple Hide My Email. Their page
- private.icloud.com
- Apple Hide My Email. Their page
- mozmail.com
- Firefox Relay. Their page
- relay.firefox.com
- Firefox Relay. Their page
- addy.io
- addy.io. Their page
- anonaddy.com
- addy.io. Their page
- anonaddy.me
- addy.io. Their page
- duck.com
- DuckDuckGo Email Protection. Their page
- 33mail.com
- 33Mail. Their page
What happens to what you type
Paste an address and, with JavaScript on, only the part after the @ leaves your browser. Without JavaScript the form sends what you typed to our server, which reduces it to the domain and opens that domain’s page. We don’t save what you check here, with one exception: the domain age tool keeps the registry’s answer for a domain in memory for up to 24 hours, so repeat checks don’t go back to the registry. It’s free, and limited to 30 checks a minute per visitor.
Need this on every signup? The API checks format, mail servers, disposable domains, role addresses and relays in one call, and the first 100 checks a month are free.
MX records checkerFree email provider checkerDomain age checker