Disposable emails, invalid addresses, and free-tier abusers inflate your sign-up numbers and corrupt your funnel analytics. Block them at the point of registration - before they touch your database.
of SaaS sign-ups may use invalid/disposable addresses on high-volume acquisition channels
BounceZero API response time - invisible to users
disposable email providers blocked
cost per blocked fake sign-up vs. cost to serve it
Users spin up multiple accounts with disposable emails to extend trials indefinitely. Each fake account consumes compute, storage, and onboarding automation spend.
Sign-up > activation > trial > paid conversion rates are meaningless when a portion of "sign-ups" were never real people. CAC and LTV models are understated.
Your confirmation emails, onboarding sequences, and product updates bounce on invalid addresses - damaging your transactional domain reputation even when you're not doing marketing.
Automated onboarding sequences fire for fake accounts. Support tickets get created. Welcome calls get booked. All waste operational resources.
Fake accounts inflate monthly active user metrics until churn catches up. This distorts investor reporting, product analytics, and team decisions.
Storing email addresses you've never verified exposes you to GDPR data minimisation questions. Verification at point of capture is a clean compliance answer.
Pick the pattern that fits your stack and risk tolerance.
Call the API on form submit, server-side. Return validation error immediately if the address is invalid or disposable. User sees the error before the form completes. Zero fake accounts enter your database.
Best for: High-value sign-up flows, paid trial starts, anything with free credits.
Accept the sign-up immediately, trigger verification in a background job. Hold access to core features (e.g., sending email, API keys) until verification passes. User gets a "check your email" gate.
Best for: High-volume consumer sign-ups where friction at the form is a concern.
Accept all sign-ups but tag them with a verification score. Route high-confidence addresses to standard onboarding; low-confidence to a reduced-feature tier or additional verification step.
Best for: PLG products with network effects where blocking too aggressively has CAC cost.
Server-side Node.js example - the API key never leaves your server.
Full examples in Python, PHP, Go, Ruby, and Java available in the API docs.
100 free verifications monthly to test your integration. Full API access on free plan.
Get API KeyFull integration guide: API Documentation
Block fake accounts at the door, not after they've caused damage
Disposable email addresses (Mailinator, TempMail, 10minutemail) are the tool of choice for users who want to bypass free-trial limits without real intent. They inflate signup numbers, corrupt A/B test results, trigger false-positive fraud alerts, and consume onboarding sequences on accounts that will never convert. BounceZero's API blocks them at form submission in under 400ms.
Users who mistype their email at signup cannot receive verification emails, password reset links, or invoices. These create support tickets (average $15-25 cost per ticket) and churn from frustrated users who can't access their accounts. Real-time email verification at signup catches typos immediately - before the account is created.
Many SaaS products see 10-30% of signups using disposable or role addresses to abuse free tier limits. BounceZero detects disposable providers (50,000+ known domains), role addresses (info@, admin@, noreply@), and invalid formats. Blocking these at signup reduces support load, credit fraud, and abuse reports while keeping trial conversion metrics clean.
Pick the workflow that matches your stack
Upload a CSV, get a clean list in minutes
Protect sender reputation before every send
Clean subscribers before your next blast
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