What are disposable emails and how to block them
Temp mail at signup, freemium fraud, and how verification API protects your product from throwaway accounts.
A disposable email is a temporary inbox created for minutes — to receive an activation link without sharing a real contact. For SaaS products this means fake metrics, trial abuse, and hard bounces on the first send.
Where it hurts most
- Freemium and trials — accounts with no payment intent.
- Lead magnets — inflated MQL counts with no follow-up path.
- Marketplaces — spam listings and fake seller accounts.
How we detect disposable addresses
EmailVerifier maintains a disposable domain database and heuristics for new temp-mail domains. Verification returns risky or invalid depending on classification confidence.
Blocking at signup
Wire POST /api/v1/verify into your signup form:
- Valid → create the user.
- Invalid / disposable → show an inline error.
- Unknown → optional async verify or manual review.
Typical latency is a few seconds — show a spinner in the form.
Do we block Gmail?
No. Free providers (Gmail, Outlook) are not blocked by default — we flag them only when you need B2B vs consumer segmentation.
Bulk vs real-time
Clean historical signups with bulk CSV. Protect new registrations with real-time API — your database stays clean without monthly manual audits.