Disposable Email Checker
Find out whether a domain is a throwaway inbox provider, checked against a list of 159,000+ known temp-mail domains.
Why disposable signups cost you money
A disposable address is a way to take something from you without giving anything back. Whatever sits behind your email gate — a free trial, a credit grant, a discount code, a downloadable report — can be claimed again and again, by the same person, with a fresh throwaway inbox each time.
The damage compounds quietly. These addresses stop accepting mail within hours, so every subsequent message you send bounces. Mailbox providers read a rising bounce rate as a signal that you are mailing a purchased or poorly maintained list, and they begin routing your legitimate mail to spam. A handful of throwaway signups can measurably depress deliverability for everyone else on your list.
They also corrupt the numbers you make decisions with. Signups look healthy; activation, retention and revenue per user quietly do not.
Disposable is not the same as free
This distinction matters more than any other on this page, and getting it wrong is expensive.
Free providers — gmail.com, outlook.com, yahoo.com — give away permanent mailboxes to real people. A large share of your genuine customers use them, particularly consumers and solo founders. Blocking them means turning away paying users.
Disposable providers give away mailboxes that destroy themselves. Nobody receives your onboarding sequence. Nobody resets a password. There is no legitimate long-term use for one on a signup form.
This tool reports both, separately, so you can block one and merely flag the other.
Where to enforce it
At registration, not at send time. Rejecting a disposable address the moment someone types it costs you nothing — they either supply a real one or they were never going to convert. Discovering it weeks later, when a campaign bounces, means the damage to your sender reputation is already done.
You can also check whether an address is syntactically valid and has real MX records, or verify a whole list at once through the Mailvalid API.
Frequently asked questions
What is a disposable email address?
An address on a domain that hands out temporary inboxes with no signup — Mailinator, 10minutemail, Guerrilla Mail and thousands of others. The inbox exists for minutes or hours, then vanishes. People use them to get past an email gate without giving you a real address.
Should I block disposable addresses at signup?
Usually yes, for anything with a cost per user: free trials, credit grants, referral bonuses. Disposable signups almost never convert, they inflate your metrics, and they let one person claim a promotion repeatedly. Block them at registration, where the friction of asking for another address is lowest.
How is this different from a free provider like Gmail?
Completely different, and conflating them is a costly mistake. gmail.com and outlook.com are free, but the mailboxes are permanent and belong to real people — a large share of legitimate customers use them. Disposable domains hand out inboxes that self-destruct. Block disposable; never block free providers.
How large is your disposable domain list?
More than 159,000 domains, and it is updated continuously. Disposable providers cycle through domains quickly to evade exactly this kind of blocking, so a static list downloaded once goes stale within weeks.
Can disposable domains evade detection?
Some try. The common tactics are registering fresh domains faster than lists update, and offering custom or private domains to paying users. No list is perfect. Detection catches the overwhelming majority of casual abuse, which is what actually costs you money.
Can I check disposable domains in bulk?
Yes. The Mailvalid API returns is_disposable on every verification, for single addresses and for bulk lists of up to 10,000 at a time — alongside SMTP mailbox confirmation, role-based detection, and catch-all detection.
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Need to verify a whole list?
This tool stops at DNS. The Mailvalid API confirms whether an individual mailbox actually exists over SMTP — in bulk, with 95%+ accuracy. Start with 100 free credits, no credit card.