Email Guard validates one email address per GET request. The check covers RFC-aware syntax, length limits, IDNA, and public-suffix rules, then suggests domain and TLD typos. It normalizes plus-tags and provider aliases, flags disposable domains, privacy relays, role addresses, and public consumer domains, and can return MX, wildcard DNS, and confidence evidence. Official SDKs are available for TypeScript, Go, Python, PHP, and Ruby. An MCP server works with coding agents. The free tier allows 10 requests per minute. Paid plans raise that limit to 30, 60, or 120 requests per minute and add teams, audit logs, and usage alerts.
Signup and lead forms were storing disposable, relay, and role addresses. Email Guard checks one address per request so a product can block those inboxes, suggest domain typos, and flag role and public-domain mail before it reaches the database.