Mailgun

Mailgun (by Sinch) is a transactional email API service for developers to send, receive, validate, and track emails at scale. The platform provides SMTP and HTTP APIs for sending email, inbound message routing, deliverability analytics, suppression management, and email validation with regional endpoints for US and EU data residency.

Mailgun publishes 8 API contracts indexed on the APIs.io network, including Domains API, Events API, Mailing Lists API, and 5 more. Tagged areas include Email, Transactional Email, SMTP, Email Verification, and Email Delivery.

The Mailgun catalog on APIs.io includes 1 Spectral governance ruleset.

Mailgun’s developer surface includes authentication, documentation, signup flow, pricing, engineering blog, and 7 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

32.6/100 thin ▬ flat Agent 19/100 agent aware Front door AI 3/6 light Heartbeat 98/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 published contract

Email Transactional Email SMTP Email Verification Email Delivery Messaging

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 32.6/100 · thin

Contract Quality 8.6 / 19

Developer Ergonomics 5.0 / 15

Access Clarity 4.7 / 15

Operational Transparency 0.3 / 10

Contract Governance 1.2 / 9

Discoverability 5.0 / 8

Regulatory Posture 2.5 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 19/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link

10 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Access Clarity scores 31.6 — up to +13.7 composite points
Contract Quality scores 45.9 — up to +13.5 composite points
Developer Ergonomics scores 33.3 — up to +13.3 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/mailgun/apis.yml: open an issue on github.com/api-evangelist/mailgun to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 2

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

SMTP

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

OpenAPI

measured — observed by APIs.io (published)

APIs 8

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

Mailgun Email Validation API

REST API for verifying email addresses in real time, bulk list validation, and deliverability scoring to reduce bounces and improve sender reputation.

Mailgun Domains API

The Domains API from Mailgun — 2 operation(s) for domains.

Mailgun Events API

The Events API from Mailgun — 1 operation(s) for events.

Mailgun Mailing Lists API

The Mailing Lists API from Mailgun — 1 operation(s) for mailing lists.

Mailgun Messages API

The Messages API from Mailgun — 2 operation(s) for messages.

Mailgun Routes API

The Routes API from Mailgun — 1 operation(s) for routes.

Mailgun Suppressions API

The Suppressions API from Mailgun — 3 operation(s) for suppressions.

Mailgun Webhooks API

The Webhooks API from Mailgun — 2 operation(s) for webhooks.

Scroll for all 8

Open Collections 9

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

Mailgun Domains API

OPEN COLLECTION

Mailgun Domains Events API

OPEN COLLECTION

Mailgun Domains Mailing Lists API

OPEN COLLECTION

Mailgun Domains Messages API

OPEN COLLECTION

Mailgun Domains Routes API

OPEN COLLECTION

Mailgun Domains Suppressions API

OPEN COLLECTION

Mailgun Domains Webhooks API

OPEN COLLECTION

Mailgun Webhooks

OPEN COLLECTION

Mailgun API

OPEN COLLECTION

Scroll for all 9

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Mailgun API Rules

48 rules · 46 errors 1 warnings 1 info

SPECTRAL

Security Posture 3

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

Mailgun Authentication

http · 1 scheme

SECURITY

Mailgun Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Mailgun Trust Center

SOC 2, ISO 27001, PCI DSS, HIPAA, GDPR

SECURITY

Agentic Access 1

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

Mailgun Agentic Access

17 operations · 8 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

Signup

Signup

DeveloperPortal

DeveloperPortal

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 3

Authentication, authorization, and security posture

TrustCenter

TrustCenter

DomainSecurity

DomainSecurity

Authentication

Authentication

Commercial 1

Pricing, plans, and the legal terms of use

Pricing

Pricing

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Source (apis.yml)

aid: mailgun
name: Mailgun
description: Mailgun (by Sinch) is a transactional email API service for developers to send, receive, validate, and track
  emails at scale. The platform provides SMTP and HTTP APIs for sending email, inbound message routing, deliverability analytics,
  suppression management, and email validation with regional endpoints for US and EU data residency.
type: Index
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/mailgun.png
x-docs-platform: redocly
x-docs-platform-confidence: high
x-docs-platform-checked: 2026-10-03
tags:
- Email
- Transactional Email
- SMTP
- Email Verification
- Email Delivery
- Messaging
tags_raw:
- Email
- Transactional Email
- SMTP
- Email Validation
- Email Delivery
- Messaging
url: https://raw.githubusercontent.com/api-evangelist/mailgun/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-05-30'
specificationVersion: '0.23'
apis:
- aid: mailgun:validate-api
  name: Mailgun Email Validation API
  description: REST API for verifying email addresses in real time, bulk list validation, and deliverability scoring to reduce
    bounces and improve sender reputation.
  humanURL: https://documentation.mailgun.com/docs/validate/api-overview
  baseURL: https://api.mailgun.net
  tags:
  - Email Verification
  - Verification
  - Deliverability
  tags_raw:
  - Email Validation
  - Verification
  - Deliverability
  properties:
  - type: Documentation
    url: https://documentation.mailgun.com/docs/validate/api-overview
- aid: mailgun:mailgun-domains-api
  name: Mailgun Domains API
  description: The Domains API from Mailgun — 2 operation(s) for domains.
  humanURL: https://documentation.mailgun.com/docs/mailgun/api-reference/
  baseURL: https://api.mailgun.net
  tags:
  - Domains
  properties:
  - type: OpenAPI
    url: openapi/mailgun-domains-api-openapi.yml
  - type: Documentation
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/
  - type: API Overview
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/api-overview
  - type: Authentication
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/mg-auth
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/mailgun/refs/heads/main/openapi/mailgun-webhooks-asyncapi.yml
- aid: mailgun:mailgun-events-api
  name: Mailgun Events API
  description: The Events API from Mailgun — 1 operation(s) for events.
  humanURL: https://documentation.mailgun.com/docs/mailgun/api-reference/
  baseURL: https://api.mailgun.net
  tags:
  - Event
  tags_raw:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/mailgun-events-api-openapi.yml
  - type: Documentation
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/
  - type: API Overview
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/api-overview
  - type: Authentication
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/mg-auth
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/mailgun/refs/heads/main/openapi/mailgun-webhooks-asyncapi.yml
- aid: mailgun:mailgun-mailing-lists-api
  name: Mailgun Mailing Lists API
  description: The Mailing Lists API from Mailgun — 1 operation(s) for mailing lists.
  humanURL: https://documentation.mailgun.com/docs/mailgun/api-reference/
  baseURL: https://api.mailgun.net
  tags:
  - Mailing Lists
  properties:
  - type: OpenAPI
    url: openapi/mailgun-mailing-lists-api-openapi.yml
  - type: Documentation
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/
  - type: API Overview
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/api-overview
  - type: Authentication
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/mg-auth
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/mailgun/refs/heads/main/openapi/mailgun-webhooks-asyncapi.yml
- aid: mailgun:mailgun-messages-api
  name: Mailgun Messages API
  description: The Messages API from Mailgun — 2 operation(s) for messages.
  humanURL: https://documentation.mailgun.com/docs/mailgun/api-reference/
  baseURL: https://api.mailgun.net
  tags:
  - Message
  tags_raw:
  - Messages
  properties:
  - type: OpenAPI
    url: openapi/mailgun-messages-api-openapi.yml
  - type: Documentation
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/
  - type: API Overview
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/api-overview
  - type: Authentication
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/mg-auth
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/mailgun/refs/heads/main/openapi/mailgun-webhooks-asyncapi.yml
- aid: mailgun:mailgun-routes-api
  name: Mailgun Routes API
  description: The Routes API from Mailgun — 1 operation(s) for routes.
  humanURL: https://documentation.mailgun.com/docs/mailgun/api-reference/
  baseURL: https://api.mailgun.net
  tags:
  - Routes
  properties:
  - type: OpenAPI
    url: openapi/mailgun-routes-api-openapi.yml
  - type: Documentation
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/
  - type: API Overview
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/api-overview
  - type: Authentication
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/mg-auth
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/mailgun/refs/heads/main/openapi/mailgun-webhooks-asyncapi.yml
- aid: mailgun:mailgun-suppressions-api
  name: Mailgun Suppressions API
  description: The Suppressions API from Mailgun — 3 operation(s) for suppressions.
  humanURL: https://documentation.mailgun.com/docs/mailgun/api-reference/
  baseURL: https://api.mailgun.net
  tags:
  - Suppressions
  properties:
  - type: OpenAPI
    url: openapi/mailgun-suppressions-api-openapi.yml
  - type: Documentation
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/
  - type: API Overview
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/api-overview
  - type: Authentication
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/mg-auth
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/mailgun/refs/heads/main/openapi/mailgun-webhooks-asyncapi.yml
- aid: mailgun:mailgun-webhooks-api
  name: Mailgun Webhooks API
  description: The Webhooks API from Mailgun — 2 operation(s) for webhooks.
  humanURL: https://documentation.mailgun.com/docs/mailgun/api-reference/
  baseURL: https://api.mailgun.net
  tags:
  - Webhook
  tags_raw:
  - Webhooks
  properties:
  - type: OpenAPI
    url: openapi/mailgun-webhooks-api-openapi.yml
  - type: Documentation
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/
  - type: API Overview
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/api-overview
  - type: Authentication
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/mg-auth
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/mailgun/refs/heads/main/openapi/mailgun-webhooks-asyncapi.yml
common:
- type: AgenticAccess
  url: agentic-access/mailgun-agentic-access.yml
- type: TrustCenter
  url: security/mailgun-trust-center.yml
- type: DomainSecurity
  url: security/mailgun-domain-security.yml
- type: Authentication
  url: authentication/mailgun-authentication.yml
- type: GitHubOrganization
  url: https://github.com/mailgun
- type: LinkedIn
  url: https://www.linkedin.com/company/mailgun
- type: Website
  url: https://www.mailgun.com
- type: Documentation
  url: https://documentation.mailgun.com/
- type: Signup
  url: https://signup.mailgun.com/new/signup
- type: Pricing
  url: https://www.mailgun.com/pricing/
- type: DeveloperPortal
  url: https://documentation.mailgun.com/
- type: Blog
  url: https://www.mailgun.com/blog/feed/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Mailgun API — frequently asked questions

Does Mailgun have an API?

Yes. APIs.io lists 8 APIs from Mailgun, including Mailgun Email Validation API, Mailgun Domains API and Mailgun Events API, and 5 more.

Is there an OpenAPI specification for the Mailgun API?

Yes. APIs.io indexes 7 OpenAPI specifications for Mailgun, each linked for download from this page.

How do I authenticate with the Mailgun API?

Mailgun uses bearer-token authentication (http · 1 scheme). The details are profiled on APIs.io as Mailgun Authentication.

Is the Mailgun API ready for AI agents?

Mailgun has a Kin Score of 32.6 out of 100 (thin) and an Agent Readiness score of 19.0 (agent-aware), scored by API Evangelist on 2026-11-06.

Compared on APIs.io

Side by side with a competitor, using the compare_providers tool: facet by facet, with the full tool response.

vs SendGrid SendGrid vs Mailgun: the email APIs, 55 points apart
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