Disposable email checker

What a disposable email address is

A disposable email address is an inbox meant to be used once and abandoned. Services such as Mailinator, Guerrilla Mail and YOPmail hand one out instantly, with no signup, so someone can receive a confirmation link without giving away their real address. Some services issue a fresh random subdomain to every visitor, which is why this checker looks at each domain and all of its parents: an address at inbox.guerrillamail.com is caught through guerrillamail.com. The glossary has a shorter definition of a disposable email address.

When blocking them is right, and when it costs you enquiries

A disposable email check earns its keep where a working address is the whole point: a free trial meant for one person, a waitlist you intend to email, a download you only send to a real inbox. A throwaway address there means you will never reach that person again, and turning it away at the form is reasonable.

A contact form is different. The person writing wants a reply, so a throwaway address usually means one of two things: a bot, or someone careful about where their address ends up. A hard block loses the second group without telling you they were ever there. Treating the address as one signal among several, and keeping whatever gets caught somewhere you can read it, costs far less.

Either way, a list is evidence, not proof. A domain that is not listed may still be throwaway, since a list only knows what someone has reported, and the list's own maintainers say they cannot guarantee every entry is still disposable. That is why this temp email checker says “not listed” rather than “safe”.

Privacy relays are real people

Hide My Email from Sign in with Apple (privaterelay.appleid.com), Firefox Relay (mozmail.com), SimpleLogin (aleeas.com) and DuckDuckGo Email Protection (duck.com) give people a forwarding address that delivers to their real inbox. They exist to hide the real address, which makes them look like throwaway ones, but someone reads what arrives and can reply. None of these domains is on the community list at the version used here. This checker labels them as relays, matches their custom subdomains too, and never counts them as disposable. Blocking them turns away people who simply care about their privacy.

How WebForms treats a disposable address

WebForms checks the email addresses in each submission against its own short list of well-known disposable services and leaves the long tail to the other layers of its filter. The setting is called Block disposable email in a form's spam settings (blockDisposableEmail in the API) and is on by default. Despite the name, it does not reject the submission. It adds to the spam score, and whether the message is quarantined depends on what else the filter finds, including the AI classifier that reads the message itself. A quarantined submission stays readable in your dashboard but is never delivered to a destination and does not count towards your monthly quota. Every layer is described in the spam protection docs.

Where the list comes from

The community list is disposable-email-domains on GitHub, published under CC0, so anyone may copy and reuse it. This page uses the version at commit e4f0910 from 23 October 2026, which lists 9,927 domains, and you can download the exact file it checks against. Matching follows the list's own instructions: an address matches when its domain, or any parent domain short of the top-level one, is listed.

Throwaway addresses are only one kind of form spam. To see what else your form is exposed to, run it through the form spam checker, or read how to stop contact form spam for the full set of defences.