---
title: "Verify an email address"
method: POST
path: "/email"
tags: ["Email"]
---

# Verify an email address

`POST /email`

## Request

- Base URL: `https://app.1lookup.io/api/v1`
- URL: `https://app.1lookup.io/api/v1/email`
- Auth: HTTP bearer

Checks that a mailbox exists and is deliverable, and flags disposable, role-based, free-provider and catch-all addresses. Costs 1 credit.

## Request body

- object
  - `email` string, required: Email address to verify.
  - `bypass_cache` boolean: Skip the 7-day result cache and run a fresh lookup. Also accepted as `bypassCache` or `forceFresh`, in the body or the query string. A cached result you ran yourself is free; a fresh lookup is charged as usual.

## Response `200`

Lookup completed. `metadata.credits_used` says what it cost.

- object
  - `success` true, required
  - `data` EmailResult, required: Email verification result.
    - `request` LookupRequest, required
      - `id` string, uuid, required: Id of this lookup.
      - `type` string, required: Lookup type, such as `phone`, `email` or `hlr_lookup`.
      - `input` string, required: The input as it was looked up, after normalization.
      - `timestamp` string, date-time, required: When the lookup ran.
      - `processing_time_ms` integer, required: Server-side processing time, in milliseconds.
    - `risk_assessment` RiskAssessment
      - `fraud_score` number: 0 to 100, higher is riskier. Not returned by every product (phone validation has none).
      - `risk_level` 'LOW' | 'MEDIUM' | 'HIGH' | 'CRITICAL', required
      - `risk_factors` string[], required: Codes for what raised the risk, such as `NOT_REACHABLE`, `DISPOSABLE_EMAIL` or `NO_MATCH_FOUND`.
      - `confidence_level` number, required: 0 to 100.
    - `classification` object, required
      - `email_type` 'BUSINESS_PERSONAL' | 'FREE_PROVIDER' | 'ROLE_BASED' | 'UNKNOWN', required
      - `provider_type` 'CORPORATE' | 'FREE' | 'DISPOSABLE'
      - `provider_tier` 'ENTERPRISE' | 'TIER_1_FREE' | 'TIER_2_FREE' | 'DISPOSABLE'
      - `deliverability_status` 'DELIVERABLE' | 'RISKY' | 'UNDELIVERABLE' | 'TEMPORARY' | 'UNKNOWN', required
      - `mailbox_verification_state` 'CONFIRMED' | 'UNCONFIRMED', required: UNCONFIRMED when the mail server would not say whether the mailbox exists.
      - `inbox_placement` 'PRIMARY' | 'PROMOTIONS' | 'SPAM' | 'UNCERTAIN'
      - `engagement_potential` 'HIGH' | 'MEDIUM' | 'LOW' | 'NONE'
    - `insights` object, required
      - `deliverability` object, required
        - `score` number
        - `factors` object
          - `mx_records` boolean, nullable: The domain publishes mail servers. null when unknown.
          - `smtp_valid` boolean, nullable: null when the mailbox could not be confirmed.
          - `mailbox_exists` boolean, nullable: null when the mailbox could not be confirmed.
          - `catch_all` boolean: The domain accepts mail for any address.
          - `greylisted` boolean
        - `upstream_verification_detail` string: Extra detail when the mailbox could not be confirmed.
      - `quality` object, required
        - `score` number
        - `syntax_valid` boolean
        - `typo_detected` boolean
        - `professional_format` boolean
        - `name_pattern` 'FIRSTNAME_DOT_LASTNAME' | 'INITIAL_DOT_LASTNAME' | 'SINGLE_NAME' | 'NAME_WITH_NUMBERS' | 'OTHER' | 'UNKNOWN'
      - `reputation` object, required
        - `domain_age_days` integer, nullable: Age of the domain in days. null when the registry gave no date.
        - `domain_reputation` string: EXCELLENT, GOOD, FAIR, POOR, LOW or UNKNOWN.
        - `spam_trap_risk` 'HIGH' | 'NONE'
        - `honeypot_risk` 'MEDIUM' | 'NONE'
      - `intelligence` object
        - `lead_score` number
        - `b2b_indicator` boolean: Not a free provider and not a role address.
        - `seniority_indicator` string
        - `department_hint` 'GENERIC' | 'PERSONAL'
      - `domain_intelligence` object: Present when domain data was available: `registration`, `infrastructure`, `technologies` and `trust_indicators`.
      - `business_profile` object: Present with `domain_intelligence`: a legitimacy score and business, trust and risk signals for the domain.
    - `recommendations` Recommendations, required
      - `primary_action` 'APPROVE' | 'VERIFY' | 'REVIEW' | 'BLOCK', required
      - `secondary_actions` string[], required
      - `user_message` string, required: One plain sentence describing the result.
      - `business_rules` object, required: Product-specific yes/no rules, such as `sms_allowed` and `voice_allowed` for a phone number.
    - `metadata` LookupMetadata, required
      - `api_version` string, required
      - `schema_version` string, required
      - `credits_used` integer: Credits this call cost. 0 for a no-match on success-billed products, and for a cached result you ran yourself.
      - `credits_remaining` integer: Credits left on the account after this call.
      - `cache_hit` boolean, required: True when the result came from the 7-day cache.
      - `cached_at` string, date-time: When the cached result was first looked up. Only on cache hits.
      - `data_sources` string[], required: Generic labels for the kinds of data consulted.
      - `fallback_used` boolean: Email verification only: a second verification ran.
      - `lookup_source` 'standard' | 'premium': Reverse phone lookup only: which record was read.

## Other responses

- `400`: `INVALID_REQUEST`: The body is not valid JSON; `MISSING_FIELD`: The request field is missing; `INVALID_INPUT`: The input is not a string, or does not match the expected format; `VALIDATION_FAILED`: The lookup could not be completed for this input. Nothing was charged; `UPSTREAM_ERROR`: The source could not answer for this input. Nothing was charged
- `401`: `UNAUTHORIZED`: Invalid or missing API key
- `402`: `INSUFFICIENT_CREDITS`: Not enough credits for the request
- `403`: `UPGRADE_REQUIRED`: The account has no paid plan, and API access needs one. Upgrade at https://app.1lookup.io/billing?tab=plan
- `429`: `RATE_LIMIT_EXCEEDED`: Too many requests
- `500`: `INTERNAL_ERROR`: Internal server error
- `503`: `SERVICE_UNAVAILABLE`: The lookup service, or the API key check, is temporarily unavailable. Nothing was charged; retry after `Retry-After` seconds; `SERVICE_BUSY`: The service is busy. Nothing was reserved or charged; retry after `Retry-After` seconds; `UPSTREAM_QUOTA_EXHAUSTED`: The lookup is temporarily unavailable on our side. Nothing was charged; retry after `Retry-After` seconds; `UPSTREAM_TIMEOUT`: The source took too long to answer. Nothing was charged; retry after `Retry-After` seconds

---

[API](https://skmtc.dev/1lookup/apis/1lookup-api.md) · [All operations](https://skmtc.dev/1lookup/apis/1lookup-api/llms.txt) · [OpenAPI document](https://skmtc.dev/1lookup/apis/1lookup-api/revisions/57b6d8ba04ac?raw)