What is a disposable email address?
Also called: temporary email, throwaway email, burner email
A disposable email address is a temporary mailbox from a service like Mailinator or 10MinuteMail, created to receive one message — usually a signup confirmation — and then abandoned. The addresses work when tested, which is why syntax and MX checks pass them, but the mailboxes are discarded within minutes or hours.
Disposable addresses are the reason a list can verify clean and still perform terribly. The domain has valid MX records and the mailbox genuinely exists at the moment of the check, so any verifier that only asks 'does this deliver?' returns valid. It just will not exist by the time you send your second email.
Detecting them means maintaining a list of the provider domains, which run into the thousands and change constantly. We block 8,740 of them, refreshed from a file rather than hardcoded so the list can be updated without a code change.
One guard matters when doing this: a disposable list must never include real mail hosts. Gmail, Outlook and the other free providers get explicitly subtracted from ours, because misclassifying them as disposable would throw away most of a typical consumer list.
Last reviewed 2026-09-11