Mailboxlayer

Real-time email validation and verification REST/JSON API operated by APILayer. Provides syntax checks, typo suggestions, MX-record lookup, SMTP verification, catch-all/role/disposable/free-provider detection, and a deliverability quality score.

Mailboxlayer publishes 3 APIs on the APIs.io network: Verification API, Bulk Check API, and Check API. Tagged areas include Email, Email Verification, Email Validation, SMTP, and MX Records.

The Mailboxlayer catalog on APIs.io includes 1 JSON-LD context and 2 Spectral governance rulesets.

Mailboxlayer’s developer surface includes authentication, developer portal, signup flow, pricing, getting-started guide, support, documentation, and 36 more developer resources.

🌐 Visit website 📡 Source on GitHub

71.9/100 exemplar ▬ flat Agent 33/100 agent ready Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemiumSelf serve⚡ Free to try

2 APIs 11 Features 6 Use Cases

Email Email Verification Email Validation SMTPMX RecordsCatch-All DetectionDisposable EmailFree Email ProviderRole AddressQuality ScoreAPILayer Public APIs Data Quality Anti-Fraud Deliverability Communications Developer Tools Security

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 71.9/100 · exemplar

Contract Quality 18.0 / 25

Developer Ergonomics 16.5 / 20

Access Clarity 16.8 / 20

Operational Transparency 6.5 / 13

Contract Governance 5.6 / 12

Discoverability 8.3 / 10

Agent readiness — 33/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 4 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Create-or-Update Ergonomics does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/mailboxlayer: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 4

Individual APIs this provider publishes, each with its own machine-readable definition.

mailboxlayer Verification API

Email address validation and verification operations.

Mailboxlayer Email Validation API

REST/JSON API for real-time email validation: syntax check, typo suggestions, MX-record lookup, SMTP verification, catch-all/role/disposable/free detection, and quality score. A...

Mailboxlayer Bulk Check API

The Bulk Check API from Mailboxlayer — 1 operation(s) for bulk check.

Mailboxlayer Check API

The Check API from Mailboxlayer — 1 operation(s) for check.

Postman Collections 1

Ready-to-run Postman collections for exercising this provider's APIs.

mailboxlayer Verification API

POSTMAN

Open Collections 3

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

mailboxlayer Verification API

OPEN COLLECTION

mailboxlayer API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Mailboxlayer Plans Pricing

5 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Mailboxlayer Rate Limits

4 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Mailboxlayer Finops

FINOPS

Features 11

Notable capabilities this provider offers.

Syntax And Typo Check

Thorough RFC 5322 syntax validation with did-you-mean suggestions for likely typos.

Real-Time SMTP Verification

Each address is pinged via SMTP to confirm the mailbox actually accepts mail.

MX Record Lookup

Verifies that the email domain has functioning MX records.

Catch-All Detection

Determines whether the recipient domain accepts mail for any local part (paid plans only).

Role Address Detection

Flags addresses associated with a function rather than a person (support@, admin@, etc.).

Free Provider Detection

Identifies addresses on free webmail providers (Gmail, Yahoo, Outlook.com, etc.).

Disposable Provider Detection

Identifies addresses on throwaway / disposable providers (mailinator.com, etc.).

Quality Score

A 0.0 to 1.0 numeric score expressing overall deliverability and quality.

HTTPS Encryption

256-bit HTTPS transport on paid plans (Basic and above).

Bulk Endpoint

Submit 25 addresses (Pro Plus) or 100 addresses (Enterprise Plus) in a single request.

JSONP Support

JSONP wrapper via the `callback` query parameter.

Scroll for all 11

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Mailboxlayer Context

2 classes · 17 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs.

Mailboxlayer API Rules

5 rules · 4 warnings 1 info

SPECTRAL

Mailboxlayer API Rules

11 rules · 6 errors 4 warnings 1 info

SPECTRAL

JSON Schema 2

Standalone JSON Schema definitions for this provider's data models.

mailboxlayer Email Check Result

12 properties

JSON SCHEMA

mailboxlayer Error Response

2 properties

JSON SCHEMA

JSON Structure 1

JSON Structure definitions describing this provider's data shapes.

Mailboxlayer Check Result Structure

12 properties

JSON STRUCTURE

Examples 6

Example request and response payloads for these APIs.

Mailboxlayer Check Disposable Example

2 fields

EXAMPLE

Mailboxlayer Check Error Example

2 fields

EXAMPLE

Mailboxlayer Check Result Example

12 fields

EXAMPLE

Mailboxlayer Check Result Free Example

12 fields

EXAMPLE

Mailboxlayer Check Success Example

2 fields

EXAMPLE

Mailboxlayer Check Typo Example

2 fields

EXAMPLE

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Mailboxlayer Authentication

apiKey · 2 schemes

SECURITY

Mailboxlayer Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Mailboxlayer Agentic Access

1 operation

1 operations · 0 acting

AGENTIC

Use Cases 6

What developers build with this provider.

Signup Form Validation

Catch typos and disposable addresses at signup before they hit your user database.

List Hygiene

Clean existing email marketing lists to lift deliverability and sender reputation.

Lead Enrichment

Enrich CRM and lead-capture records with deliverability scores and role flags.

Fraud And Abuse Prevention

Block disposable email providers commonly used for trial abuse and chargebacks.

Transactional Email Hygiene

Reduce hard-bounces from order receipts, password resets, and notifications.

B2B Sales Qualification

Separate role addresses and free-provider addresses from individual corporate inboxes.

Integrations 7

Pre-built integrations with other platforms and tools.

PostHog

Plugin scoring incoming PostHog user emails via the mailboxlayer API.

Fortinet FortiSOAR

Connector for incorporating email verification into security orchestration playbooks.

Laravel

Multiple community Laravel packages wrap mailboxlayer for PHP web applications.

Symfony

Symfony bundle for mailboxlayer-backed email validation.

Node.js / TypeScript

Node and TypeScript client libraries for serverside email verification.

Ruby

Ruby client gem.

Delphi

Delphi sample demonstrating the API for desktop application validation.

Scroll for all 7

Solutions 5

Packaged solutions this provider offers.

Free

100 requests/month, HTTP only, no support, no catch-all detection.

Basic

$14.99/mo for 5,000 requests; HTTPS, catch-all detection, standard support.

Professional Plus

$74.99/mo for 50,000 requests; adds bulk endpoint (25 emails).

Enterprise Plus

$249.99/mo for 250,000 requests; adds bulk endpoint (100 emails) and richer SLAs.

Custom

Contact sales for higher volumes and bespoke arrangements.

Resources

Get Started 5

Portal, sign-up, and the first successful call

Portal

Signup

GettingStarted

DeveloperPortal

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Lifecycle

Conventions

ErrorCatalog

DataModel

Conformance

SpectralRules

Vocabulary

Scroll for all 7

Build 8

SDKs, sample code, and the tooling you integrate with

PostmanWorkspace

PostmanWorkspace

Packages

Packages

GitHubOrganization

GitHubRepository

SDKs

SDKs

SDKs

SDKs

Scroll for all 8

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 7

Status, limits, changes, and where to get help

IssueTracker

Support

HelpCenter

Community

FAQ

StatusPage

RateLimits

Scroll for all 7

Commercial 5

Pricing, plans, and the legal terms of use

Pricing

TermsOfService

PrivacyPolicy

Plans

FinOps

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

Overlay

Overlay

PublicAPIsListing

PublicAPIsListing

Source (apis.yml)

aid: mailboxlayer
name: Mailboxlayer
description: Real-time email validation and verification REST/JSON API operated by APILayer. Provides syntax checks, typo
  suggestions, MX-record lookup, SMTP verification, catch-all/role/disposable/free-provider detection, and a deliverability
  quality score.
url: https://mailboxlayer.com
deliveryModel:
  model: unknown
  open_source: unknown
  commercial: true
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  - pricing
  - repository-unlicensed
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  - rate-limits
  - security
  - sandbox
  generated: '2026-09-03'
  method: derived
image: https://mailboxlayer.com/site_images/mailboxlayer_logo_white.svg
specificationVersion: '0.23'
created: '2026-05-28'
modified: '2026-08-14'
x-source: public-apis/public-apis
x-category: Email
x-tier: 3
x-tier-reason: bulk-registered-from-public-apis
x-type: company
tags:
- Email
- Email Verification
- Email Validation
- SMTP
- MX Records
- Catch-All Detection
- Disposable Email
- Free Email Provider
- Role Address
- Quality Score
- APILayer
- Public APIs
- Data Quality
- Anti-Fraud
- Deliverability
- Communications
- Developer Tools
- Security
tags_raw:
- Email
- Email Verification
- Email Validation
- SMTP
- MX Records
- Catch-All Detection
- Disposable Email
- Free Email Provider
- Role Address
- Quality Score
- apilayer
- Public APIs
- Data Quality
- Anti-Fraud
- Deliverability
- Communications
- Developer Tools
- Security
apis:
- aid: mailboxlayer:mailboxlayer-verification-api
  name: mailboxlayer Verification API
  description: Email address validation and verification operations.
  humanURL: https://mailboxlayer.com
  baseURL: https://apilayer.net/api
  tags:
  - Verification
  properties:
  - type: OpenAPI
    url: openapi/mailboxlayer-verification-api-openapi.yml
  - type: Documentation
    url: https://docs.apilayer.com/mailboxlayer/docs/api-documentation
  - type: APIReference
    url: https://docs.apilayer.com/mailboxlayer/docs/api-documentation
  - type: GettingStarted
    url: https://mailboxlayer.com/quickstart
  - type: Authentication
    url: https://docs.apilayer.com/mailboxlayer/docs/api-documentation
  - type: JSONSchema
    url: json-schema/mailboxlayer-check-result-schema.json
  - type: JSONSchema
    url: json-schema/mailboxlayer-error-schema.json
  - type: JSONStructure
    url: json-structure/mailboxlayer-check-result-structure.json
  - type: JSONLD
    url: json-ld/mailboxlayer-context.jsonld
  - type: Examples
    url: examples/mailboxlayer-check-success-example.json
  - type: Examples
    url: examples/mailboxlayer-check-typo-example.json
  - type: Examples
    url: examples/mailboxlayer-check-disposable-example.json
  - type: Examples
    url: examples/mailboxlayer-check-error-example.json
  - type: Examples
    url: examples/mailboxlayer-check-result-example.json
  - type: Examples
    url: examples/mailboxlayer-check-result-free-example.json
  - type: RateLimits
    url: rate-limits/mailboxlayer-rate-limits.yml
  - type: OpenAPI
    name: mailboxlayer API (provider-published, SwaggerHub OpenAPI 3.1.0)
    url: openapi/_original/mailboxlayer-swaggerhub-openapi.json
  - type: Overlay
    url: overlays/mailboxlayer-verification-api-overlay.yaml
  - type: Conventions
    url: conventions/mailboxlayer-conventions.yml
  - type: ErrorCatalog
    url: errors/mailboxlayer-problem-types.yml
  - type: DataModel
    url: data-model/mailboxlayer-data-model.yml
- name: Mailboxlayer Email Validation API
  description: 'REST/JSON API for real-time email validation: syntax check, typo suggestions, MX-record lookup, SMTP verification,
    catch-all/role/disposable/free detection, and quality score. Available via legacy apilayer.net endpoint (access_key query
    param) and APILayer marketplace endpoint (apikey header).'
  humanURL: https://mailboxlayer.com/documentation
  baseURL: https://apilayer.net/api/check
  tags:
  - Email Validation
  - Email Verification
  - Data Quality
  - Anti-Fraud
  - Deliverability
  - Communications
  - Developer Tools
  - Security
  properties:
  - type: Documentation
    url: https://mailboxlayer.com/documentation
  - type: Documentation
    url: https://docs.apilayer.com/mailboxlayer/docs/api-documentation
- aid: mailboxlayer:mailboxlayer-bulk-check-api
  name: Mailboxlayer Bulk Check API
  description: The Bulk Check API from Mailboxlayer — 1 operation(s) for bulk check.
  humanURL: https://mailboxlayer.com
  baseURL: https://apilayer.net/api
  tags:
  - Bulk Check
  properties:
  - type: OpenAPI
    url: openapi/mailboxlayer-bulk-check-api-openapi.yml
- aid: mailboxlayer:mailboxlayer-check-api
  name: Mailboxlayer Check API
  description: The Check API from Mailboxlayer — 1 operation(s) for check.
  humanURL: https://mailboxlayer.com
  baseURL: https://apilayer.net/api
  tags:
  - Check
  properties:
  - type: OpenAPI
    url: openapi/mailboxlayer-check-api-openapi.yml
common:
- type: IssueTracker
  url: https://github.com/apilayer/mailboxlayer-API/issues
- type: PostmanWorkspace
  url: https://www.postman.com/kinlaneapi/mailboxlayer/overview
- type: AgenticAccess
  url: agentic-access/mailboxlayer-agentic-access.yml
- type: DomainSecurity
  url: security/mailboxlayer-domain-security.yml
- type: Authentication
  url: authentication/mailboxlayer-authentication.yml
- type: Website
  url: https://mailboxlayer.com
- type: Portal
  url: https://mailboxlayer.com/dashboard
- type: Signup
  url: https://mailboxlayer.com/product
- type: Pricing
  url: https://mailboxlayer.com/product
- type: GettingStarted
  url: https://mailboxlayer.com/quickstart
- type: TermsOfService
  url: https://mailboxlayer.com/terms
- type: PrivacyPolicy
  url: https://mailboxlayer.com/privacy
- type: Support
  url: https://apilayer.com/support/
- type: HelpCenter
  url: https://mailboxlayer.com/contact
- type: Community
  name: APILayer Discord
  url: https://discord.com/invite/hgjA78638n
- type: DeveloperPortal
  url: https://docs.apilayer.com/mailboxlayer/
- type: Documentation
  url: https://docs.apilayer.com/mailboxlayer/docs/api-documentation
- type: APIReference
  url: https://docs.apilayer.com/mailboxlayer/docs/mailboxlayer-api-v-1-0-0
- type: Blog
  url: https://blog.apilayer.com/
- type: FAQ
  url: https://mailboxlayer.com/faq
- type: StatusPage
  url: https://mailboxlayer.com/api-status
- type: Lifecycle
  url: lifecycle/mailboxlayer-lifecycle.yml
- type: Sandbox
  name: APILayer Developers Playground
  url: https://apilayer.com/playground/
- type: Conventions
  url: conventions/mailboxlayer-conventions.yml
- type: ErrorCatalog
  url: errors/mailboxlayer-problem-types.yml
- type: DataModel
  url: data-model/mailboxlayer-data-model.yml
- type: Conformance
  url: conformance/mailboxlayer-conformance.yml
- type: Packages
  url: packages/mailboxlayer-packages.yml
- type: LLMsTxt
  url: llms/mailboxlayer-llms.txt
- type: AgentSkill
  url: skills/_index.yml
- type: Overlay
  url: overlays/mailboxlayer-verification-api-overlay.yaml
- type: GitHubOrganization
  url: https://github.com/apilayer
- type: GitHubRepository
  url: https://github.com/apilayer/mailboxlayer-API
- type: SDKs
  name: Laravel mailboxlayer
  url: https://github.com/ash-jc-allen/laravel-mailboxlayer
- type: SDKs
  name: actfong/mailboxlayer (Ruby)
  url: https://github.com/actfong/mailboxlayer
- type: SDKs
  name: damienmarchandfr/mailboxlayer-node-client (Node/TypeScript)
  url: https://github.com/damienmarchandfr/mailboxlayer-node-client
- type: SDKs
  name: mailboxlayerbundle (Symfony)
  url: https://github.com/ylly/mailboxlayerbundle
- type: Integrations
  name: PostHog
  url: https://github.com/PostHog/mailboxlayer-plugin
- type: Integrations
  name: Fortinet FortiSOAR
  url: https://github.com/fortinet-fortisoar/connector-mailboxlayer
- type: SpectralRules
  url: rules/mailboxlayer-rules.yml
- type: Vocabulary
  url: vocabulary/mailboxlayer-vocabulary.yml
- type: PublicAPIsListing
  url: https://github.com/public-apis/public-apis
- type: Plans
  url: plans/mailboxlayer-plans-pricing.yml
- type: RateLimits
  url: rate-limits/mailboxlayer-rate-limits.yml
- type: FinOps
  url: finops/mailboxlayer-finops.yml
- type: Features
  data:
  - name: Syntax And Typo Check
    description: Thorough RFC 5322 syntax validation with did-you-mean suggestions for likely typos.
  - name: Real-Time SMTP Verification
    description: Each address is pinged via SMTP to confirm the mailbox actually accepts mail.
  - name: MX Record Lookup
    description: Verifies that the email domain has functioning MX records.
  - name: Catch-All Detection
    description: Determines whether the recipient domain accepts mail for any local part (paid plans only).
  - name: Role Address Detection
    description: Flags addresses associated with a function rather than a person (support@, admin@, etc.).
  - name: Free Provider Detection
    description: Identifies addresses on free webmail providers (Gmail, Yahoo, Outlook.com, etc.).
  - name: Disposable Provider Detection
    description: Identifies addresses on throwaway / disposable providers (mailinator.com, etc.).
  - name: Quality Score
    description: A 0.0 to 1.0 numeric score expressing overall deliverability and quality.
  - name: HTTPS Encryption
    description: 256-bit HTTPS transport on paid plans (Basic and above).
  - name: Bulk Endpoint
    description: Submit 25 addresses (Pro Plus) or 100 addresses (Enterprise Plus) in a single request.
  - name: JSONP Support
    description: JSONP wrapper via the `callback` query parameter.
- type: UseCases
  data:
  - name: Signup Form Validation
    description: Catch typos and disposable addresses at signup before they hit your user database.
  - name: List Hygiene
    description: Clean existing email marketing lists to lift deliverability and sender reputation.
  - name: Lead Enrichment
    description: Enrich CRM and lead-capture records with deliverability scores and role flags.
  - name: Fraud And Abuse Prevention
    description: Block disposable email providers commonly used for trial abuse and chargebacks.
  - name: Transactional Email Hygiene
    description: Reduce hard-bounces from order receipts, password resets, and notifications.
  - name: B2B Sales Qualification
    description: Separate role addresses and free-provider addresses from individual corporate inboxes.
- type: Integrations
  data:
  - name: PostHog
    description: Plugin scoring incoming PostHog user emails via the mailboxlayer API.
  - name: Fortinet FortiSOAR
    description: Connector for incorporating email verification into security orchestration playbooks.
  - name: Laravel
    description: Multiple community Laravel packages wrap mailboxlayer for PHP web applications.
  - name: Symfony
    description: Symfony bundle for mailboxlayer-backed email validation.
  - name: Node.js / TypeScript
    description: Node and TypeScript client libraries for serverside email verification.
  - name: Ruby
    description: Ruby client gem.
  - name: Delphi
    description: Delphi sample demonstrating the API for desktop application validation.
- type: Solutions
  data:
  - name: Free
    description: 100 requests/month, HTTP only, no support, no catch-all detection.
  - name: Basic
    description: $14.99/mo for 5,000 requests; HTTPS, catch-all detection, standard support.
  - name: Professional Plus
    description: $74.99/mo for 50,000 requests; adds bulk endpoint (25 emails).
  - name: Enterprise Plus
    description: $249.99/mo for 250,000 requests; adds bulk endpoint (100 emails) and richer SLAs.
  - name: Custom
    description: Contact sales for higher volumes and bespoke arrangements.
x-enrichment:
  date: '2026-08-14'
  status: enriched
  artifacts_added: 10
  pass: local-v1
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APILayer
  url: https://apilayer.com/products/mailboxlayer/
generated:
  by: apis.io/add
  model: claude-opus-4-8
  confidence: 90
  at: '2026-08-14T09:35:03.920Z'

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