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Email validation API

Stop bad emails before they enter your funnel

Validate syntax, catch disposable inboxes, and classify relay and role addresses in a single request—so every signup, lead, and checkout starts clean.

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One GET returns every signal — scroll to see each check in action.

See the detection timeline

Signals per lookup

8+ characteristics

Disposable coverage

Curated data + live DNS

Integration

REST API with SDKs

Detection

Every signal in one response

EmailGuard runs RFC-aware syntax checks, normalization, and classification for roles, consumer domains, privacy relays, and disposable hosts—returned as structured JSON from GET /api/v1/emails/detect. Read the guides in our knowledge base for each field.

Email detection overview · API reference

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Create a free account, grab an API key, read the detection signal guides, or follow the disposable-email signup guide for server-side integration patterns.

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Syntax validation
RFC-aware parsing catches malformed addresses and invalid suffixes using IANA root zone and Public Suffix List data before they pollute your database.
Example address for syntax validation
Finding:Invalid TLD. `.notreal` is not in the IANA list. Further checks are skipped when syntax fails.
API response
{ "code": "SUCCESS", "message": "ok", "data": { "email": "user@example.notreal", "syntax_validation": false, "normalized": "user@example.notreal" } }
Normalization
Deduplicate signups by canonicalizing local parts, domains, and subaddressing variants.
Example address for normalization
Finding:Plus-tag and dot variants collapse to one canonical Gmail address. Flag subaddressing for routing rules.
API response
{ "code": "SUCCESS", "message": "ok", "data": { "email": "jane.doe+newsletter@gmail.com", "syntax_validation": true, "normalized": "janedoe@gmail.com", "subaddressing": true } }
Role address detection
Flag info@, support@, and other shared inboxes so sales and marketing lists stay personal.
Example address for role detection
Finding:Local part matches a shared inbox prefix. Route to support queues, not personal outreach.
API response
{ "code": "SUCCESS", "message": "ok", "data": { "email": "admin@example.com", "syntax_validation": true, "role_address": true } }
Public domain detection
Identify consumer mail providers when B2B fit or lead scoring depends on corporate domains.
Example address for public domain detection
Finding:Domain is a known freemail provider. Useful for ICP filters and enrichment workflows.
API response
{ "code": "SUCCESS", "message": "ok", "data": { "email": "alex.user@gmail.com", "syntax_validation": true, "public_domain": true } }
Relay domain detection
Identify Apple Hide My Email, Firefox Relay, and other forwarding providers that skew engagement metrics.
Example address for relay detection
Finding:Domain is a Proton Pass relay. Treat as masked identity, not a direct personal inbox.
API response
{ "code": "SUCCESS", "message": "ok", "data": { "email": "user@passmail.net", "syntax_validation": true, "relay_domain": true, "relay_provider": "protonmail" } }
Disposable detection
Block throwaway inboxes with continuously updated domain intelligence and live DNS for domains that have not yet hit public blocklists.
Example address for disposable detection
Finding:Domain classified as disposable. Block at signup before the address enters your CRM.
API response
{ "code": "SUCCESS", "message": "ok", "data": { "email": "user@throwaway.example", "syntax_validation": true, "disposable": true, "detection_source": "precomputed" } }