Stop fake signups & disposable emails at the Edge.
Real-time email risk intelligence for modern SaaS, trials, and AI agents. Detect hundreds of thousands of disposable domains, normalize canonical aliases, and prevent promo abuse in real time.
Proportionate Friction Over Blanket Rejection
Naive email blockers cost revenue by rejecting good customers. CheckSignup evaluates each input into 3 clear policy directives.
Legitimate Clean Signups
Valid corporate mailboxes or personal webmails with established DNS MX records. Zero friction onboarding.
- ✓ Grant full free trial & API credits immediately
- ✓ No secondary SMS or CAPTCHA required
- ✓ High-confidence conversion path
Conditional Friction
Privacy forwarding relays, shared role mailboxes (admin@, support@), or likely domain typos (gmial.com).
- ✓ Suggest typo fix to save the signup
- ✓ Require email verification OTP before bonus credits
- ✓ Flag for manual review on suspicious billing transactions
Hard Abuse Prevention
Temporary burner inboxes (GuerrillaMail, TempMail), invalid RFC syntax, or non-existent DNS MX records.
- ✓ Block registration immediately at form level
- ✓ Prevent promo voucher and AI token draining
- ✓ Save downstream welcome email delivery costs
Integrate in Under 2 Minutes
Native Model Context Protocol (MCP) server support, standard OpenAPI 3.0 schema, and plug-and-play recipes for modern frameworks.
Engineered for High-Velocity Signups
All validations execute in-memory on distributed edge computing nodes with zero cold-start delay.
Deterministic Canonical Normalization
Automatically collapses provider-specific aliases (e.g. john.doe+promo@gmail.com → johndoe@gmail.com) to prevent duplicate trial account farms.
Hundreds of Thousands of Disposable Domains
Comprehensive threat intelligence identifying hundreds of thousands of disposable and burner domains, updated continuously with strict whitelists protecting legitimate inboxes.
Live Domain Verification Engine
Validates active mail delivery status in real time with high-speed parallel verification and sub-150ms graceful degradation protection.
Rotating Network Detection
Identifies rotating disposable mail networks and burner relays even when throwaway domains disguise their apex names.
Fuzzy Typo Recovery
Recovers genuine user signups with subtle domain typos (@gmial.com → @gmail.com) to boost your signup conversion rates.
Zero Plaintext PII Storage
Strict GDPR Article 30 isolation. Only cryptographic SHA-256(email) and domain metadata are ever stored in audit logs.
Simple, Value-Driven Plans
Start free during development and prototyping. Scale seamlessly as your active user base grows.
Free
- 5,000 validations / month
- 1 RPS rate limit
- Full 3-State policy directives
- Live Sandbox & MCP tool
- API Key included
- Community support
Indie
- 25,000 validations / month
- 5 RPS rate limit
- Canonical alias detection
- Typo suggestion engine
- Email balance alerts
- Standard email support
Builder
- 100,000 validations / month
- 10 RPS rate limit
- Multiple API keys
- Multi-environment support
- 30-day analytics history
- Priority support response
Growth
- 500,000 validations / month
- 25 RPS rate limit
- High-volume batch endpoints
- Extended audit log retention
- Prioritized Edge routing
- Dedicated support channel
Everything You Need to Know
Common questions about CheckSignup architecture, privacy, and integration.
john.doe+1@gmail.com and j.o.h.n.d.o.e@gmail.com both deliver to johndoe@gmail.com. CheckSignup deterministically normalizes these aliases to their canonical root string, allowing your database to enforce unique user registration constraints.SHA-256(email) digest alongside domain metadata. Learn more in our Privacy Policy.degraded: true rather than hanging your user's registration form.