Block fake emails at the signup form

The problem

Fake signups are expensive: disposable addresses abuse free trials, typos mean your onboarding emails never arrive, and bots stuff your database with garbage that skews every metric downstream. Cleaning it up later costs far more than catching it at the point of capture.

The solution

Call POST /api/verify in real time as users sign up. Local checks (syntax, disposable-domain, MX, role) return in milliseconds — fast enough to validate inline before the form submits — and the full SMTP handshake confirms the mailbox in the background. Reject or flag bad addresses before they ever become rows in your database.

• Millisecond local checks: syntax, disposable, MX, and role detection run inline at form-submit speed.
• Disposable detection: block throwaway inboxes from abusing trials and promos.
• Typo catching: syntax + MX checks catch gmial.com-style mistakes before they become dead accounts.
• Simple semantics: 402 means out of credits, 429 means slow down — errors your developers already understand.