Email Guard

About

Email Guard checks an address before it is stored. One API call validates syntax, suggests domain typos, detects disposable inboxes, and flags role addresses, privacy relays, and public-domain mail. The free tier allows 10 requests per minute. It does not verify SMTP mailboxes or clean bulk lists. It is built for backend engineers and technical founders who want validation on signup, checkout, or lead capture. One request to the detect endpoint returns RFC-aware syntax checks, including length limits, IDNA, IANA, and public-suffix checks. A mistyped domain or TLD can come back as a suggested address or suggested domain. Plus-tags and provider aliases are collapsed to one mailbox. Disposable detection uses curated domain data and live DNS when needed, and the response names the detection source. The same call flags a privacy relay and the relay provider, marks role addresses, and marks public or consumer domains. Optional evidence can include an MX record, wildcard DNS, an infrastructure cluster match, a confidence value, a policy, and a suggested action. Those fields do not verify that an SMTP mailbox accepts mail, and the product does not clean bulk lists. Official SDKs ship for TypeScript, Go, Python, PHP, and Ruby. An MCP server works with Cursor, Claude Desktop, and other MCP clients. Free browser tools cover syntax, disposable addresses, role addresses, normalization, relays, public domains, and the full validator. API keys are scoped. Rate limits follow the plan: 10 requests per minute on the free tier, then 30, 60, and 120 on the paid tiers. Paid plans add teams, role-based access, audit logs, usage quotas, and usage alerts. Billing is monthly or annual in USD. Annual billing is about two months free. Every paid tier includes the full detection stack. Query add-ons stack on the monthly quota. The free tier is a rate-limited plan, not an unlimited free-forever product. Comparison pages are published for Kickbox, ZeroBounce, NeverBounce, and Mailgun Validate. Zapier is not enabled. Cold-email deliverability is outside the product.

Key Features