Email Privacy Checker

Disposable email services (Mailinator, 10minutemail, Guerrilla Mail, etc.) issue temporary inboxes used to dodge marketing lists or game free-tier signups. There are roughly 4,000 known disposable domains, maintained in public lists like disposable-email-domains on GitHub.

This checker matches an email's domain against a current snapshot of those lists and returns whether it's flagged as throwaway.

Disposable email emerged in the early 2000s as a privacy and anti-spam tactic. The first major service, Mailinator, launched in 2003 with the simple mechanic of accepting mail to any address @mailinator.com without registration. Modern variants split into a few categories: pure disposable (Mailinator, 10minutemail, Guerrilla Mail) where addresses are public and ephemeral; alias services (SimpleLogin, AnonAddy) where users get unique addresses that forward to real inboxes; and platform forwarders (Apple Hide My Email, DuckDuckGo Email Protection, Firefox Relay) which are real addresses tied to user accounts. Open-source domain lists like disposable-email-domains on GitHub track around 4,000 disposable domains; the list updates several times monthly as new services launch.

A worked example: someone signs up for a SaaS trial with `test@mailinator.com`. The checker matches mailinator.com against the disposable list and flags the address. The application can then either block the signup, require additional verification (phone, payment method), or accept it with a flag for downstream filtering. Compare to `test@hide.my.email` (Apple's privacy relay) — flagged by some lists as suspicious, but the user is real and receives mail. The same submission via SimpleLogin (`abc123@example.com` mapping to a real inbox) wouldn't appear on most disposable lists at all because the domain is the user's own custom one. False negatives are common; false positives less so but still happen.

Limitations: list-based detection has inherent lag. New disposable services don't appear on lists until someone reports them. A domain not on the list might still be disposable. Conversely, some legitimate services with dynamic subdomains (corporate email aliases, departmental mailing lists) get incorrectly flagged. The checker doesn't validate whether the address actually receives mail — it's a domain reputation check, not a deliverability test. For high-stakes applications, combine with SMTP verification, SPF/DKIM/DMARC checks, and behavioral signals (account activity, payment method).