Disposable email report: 4tmail.net
Mailboxes hosted at 4tmail.net are issued by a public, throwaway inbox service. Addresses are short-lived and exhibit repeated signup-and-discard behavior, which makes them a common vehicle for trial abuse, voucher farming and repeated account creation.
Our crawlers and signal pipeline have observed 4tmail.net across multiple disposable-domain registries and similar disposable-domain signal sources. Operators can sign up, receive a confirmation email, click the link and discard the address within minutes — bypassing standard email-confirmation flows. We strongly recommend rejecting registrations from this domain at the form level.
Signals & methodology
The classification combines data from several independent sources: curated public throwaway-domain registries that we re-sync daily, behavioral signals from our own verification traffic (mailbox lifetime, time-to-first-bounce, signup-to-deletion patterns), and operator fingerprints on the inbound MX record. A domain only ends up on the disposable list when at least two of these signals agree, which keeps the false-positive rate low even for newly launched throwaway services that haven't yet appeared on community lists.
How to handle this in your product
The cleanest place to enforce this is at the signup form itself: call the API the moment the user blurs out of the email field and reject the submission before any database row is written, so the user can correct it without an account being half-created. If you can't add a synchronous check, a second line of defence is to refuse password creation or first login for users whose domain returns the disposable verdict — that still blocks the abuse before the account becomes useful, while keeping your form code free of network calls.
This report is generated by the RiskMail Email Risk API and reflects the most recent signal pipeline run for 4tmail.net.