UserCheck (formerly MailCheck.ai)
mailcheck.aiAn email validation API that detects and blocks disposable, temporary, forwarding, and public email addresses to prevent fake user signups.
The UserCheck (formerly MailCheck.ai) API uses bearer token authentication; has freemium pricing; offers a free tier (Free plan: 1,000 credits per month, 1 request per second, no credit card required); rate limits: Free plan: 1 request/second; Pro: 5-50 req/s; Unauthenticated: 5 requests/hour; 429 on exceed. Verified 2026-07-08 with per-field source links.
Free tier
Free plan: 1,000 credits per month, 1 request per second, no credit card required
usercheck.com ↗Pricing
Free $0/month (1,000 credits/mo); Pro paid plans (custom credits, 5-50 req/s); Enterprise custom/contact sales
usercheck.com ↗Rate limits
Free plan: 1 request/second; Pro: 5-50 req/s; Unauthenticated: 5 requests/hour; 429 on exceed
usercheck.com ↗OpenAPI spec
not documented null
no sourceMCP server
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no source