EmailEngine

EmailEngine is a self-hosted email automation platform that provides a unified REST API for accessing email accounts via IMAP, SMTP, the Gmail API, and the Microsoft Graph API. It exposes JSON payloads, real-time webhooks, OAuth2 integration, an IMAP/SMTP proxy, hosted authentication forms, low-code custom integrations, Prometheus monitoring, and bounce detection so developers can build modern email functionality without paying per-account fees.

EmailEngine publishes 13 APIs on the APIs.io network, including Account API, Accounts API, Autoconfig API, and 10 more. Tagged areas include Email, Email API, IMAP, SMTP, and Webhook.

EmailEngine’s developer surface includes documentation, API reference, engineering blog, FAQ, pricing, support, and 11 more developer resources.

🌐 Visit website 📡 Source on GitHub

27.1/100 thin ▬ flat Agent 22/100 agent aware Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemium

13 APIs

Email Email API IMAP SMTP Webhook

Kin Score

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

Composite quality — 27.1/100 · thin

Contract Quality 0.0 / 23

Developer Ergonomics 4.3 / 18

Access Clarity 8.5 / 18

Operational Transparency 5.5 / 12

Contract Governance 0.0 / 11

Discoverability 6.7 / 9

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 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

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.

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/emailengine: 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 13

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

EmailEngine Account API

The Account API from EmailEngine — 3 operation(s) for account.

EmailEngine Accounts API

The Accounts API from EmailEngine — 1 operation(s) for accounts.

EmailEngine Autoconfig API

The Autoconfig API from EmailEngine — 1 operation(s) for autoconfig.

EmailEngine Deliverytest API

The Deliverytest API from EmailEngine — 1 operation(s) for deliverytest.

EmailEngine Gateways API

The Gateways API from EmailEngine — 1 operation(s) for gateways.

EmailEngine License API

The License API from EmailEngine — 1 operation(s) for license.

EmailEngine Logs API

The Logs API from EmailEngine — 1 operation(s) for logs.

EmailEngine Oauth2 API

The Oauth2 API from EmailEngine — 1 operation(s) for oauth2.

EmailEngine Outbox API

The Outbox API from EmailEngine — 1 operation(s) for outbox.

EmailEngine Stats API

The Stats API from EmailEngine — 1 operation(s) for stats.

EmailEngine Templates API

The Templates API from EmailEngine — 1 operation(s) for templates.

EmailEngine Tokens API

The Tokens API from EmailEngine — 1 operation(s) for tokens.

EmailEngine Webhookroutes API

The Webhookroutes API from EmailEngine — 1 operation(s) for webhookroutes.

Scroll for all 13

Open Collections 15

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

API Collection

OPEN COLLECTION

EmailEngine Account API

OPEN COLLECTION

EmailEngine Account Accounts API

OPEN COLLECTION

EmailEngine Account Autoconfig API

OPEN COLLECTION

EmailEngine Account Deliverytest API

OPEN COLLECTION

EmailEngine Account Gateways API

OPEN COLLECTION

EmailEngine Account License API

OPEN COLLECTION

EmailEngine Account Logs API

OPEN COLLECTION

EmailEngine Account Oauth2 API

OPEN COLLECTION

EmailEngine Account Outbox API

OPEN COLLECTION

EmailEngine Account Stats API

OPEN COLLECTION

EmailEngine Account Templates API

OPEN COLLECTION

EmailEngine Account Tokens API

OPEN COLLECTION

EmailEngine Account Webhookroutes API

OPEN COLLECTION

EmailEngine API

OPEN COLLECTION

Scroll for all 15

Pricing Plans 1

Published pricing tiers and plan structures.

Emailengine Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Emailengine Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Emailengine Finops

FINOPS

Security Posture 1

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

Emailengine Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Emailengine Agentic Access

15 operations · 1 acting

AGENTIC

Resources

Documentation 3

Reference material describing how the API behaves

ContributionGuide

ContributionGuide

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Webhooks

Webhooks

Build 2

SDKs, sample code, and the tooling you integrate with

CodeOfConduct

CodeOfConduct

SourceCode

SourceCode

Access & Security 2

Authentication, authorization, and security posture

SecurityPolicy

SecurityPolicy

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

Releases

Releases

FAQ

FAQ

Support

Support

Commercial 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: emailengine
name: EmailEngine
description: EmailEngine is a self-hosted email automation platform that provides a unified REST API for accessing email accounts
  via IMAP, SMTP, the Gmail API, and the Microsoft Graph API. It exposes JSON payloads, real-time webhooks, OAuth2 integration,
  an IMAP/SMTP proxy, hosted authentication forms, low-code custom integrations, Prometheus monitoring, and bounce detection
  so developers can build modern email functionality without paying per-account fees.
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: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/emailengine.png
type: Index
tags:
- Email
- Email API
- IMAP
- SMTP
- Webhook
tags_raw:
- Email
- Email API
- IMAP
- SMTP
- Webhooks
url: https://raw.githubusercontent.com/api-evangelist/emailengine/refs/heads/main/apis.yml
created: '2025-02-06'
modified: '2026-05-19'
specificationVersion: '0.23'
access: 3rd-Party
position: Consuming
apis:
- aid: emailengine:emailengine-account-api
  name: EmailEngine Account API
  description: The Account API from EmailEngine — 3 operation(s) for account.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Account
  properties:
  - type: OpenAPI
    url: openapi/emailengine-account-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-accounts-api
  name: EmailEngine Accounts API
  description: The Accounts API from EmailEngine — 1 operation(s) for accounts.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Account
  tags_raw:
  - Accounts
  properties:
  - type: OpenAPI
    url: openapi/emailengine-accounts-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-autoconfig-api
  name: EmailEngine Autoconfig API
  description: The Autoconfig API from EmailEngine — 1 operation(s) for autoconfig.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Autoconfig
  properties:
  - type: OpenAPI
    url: openapi/emailengine-autoconfig-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-deliverytest-api
  name: EmailEngine Deliverytest API
  description: The Deliverytest API from EmailEngine — 1 operation(s) for deliverytest.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Deliverytest
  properties:
  - type: OpenAPI
    url: openapi/emailengine-deliverytest-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-gateways-api
  name: EmailEngine Gateways API
  description: The Gateways API from EmailEngine — 1 operation(s) for gateways.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Gateways
  properties:
  - type: OpenAPI
    url: openapi/emailengine-gateways-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-license-api
  name: EmailEngine License API
  description: The License API from EmailEngine — 1 operation(s) for license.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - License
  properties:
  - type: OpenAPI
    url: openapi/emailengine-license-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-logs-api
  name: EmailEngine Logs API
  description: The Logs API from EmailEngine — 1 operation(s) for logs.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Logs
  properties:
  - type: OpenAPI
    url: openapi/emailengine-logs-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-oauth2-api
  name: EmailEngine Oauth2 API
  description: The Oauth2 API from EmailEngine — 1 operation(s) for oauth2.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Authentication
  tags_raw:
  - Oauth2
  properties:
  - type: OpenAPI
    url: openapi/emailengine-oauth2-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-outbox-api
  name: EmailEngine Outbox API
  description: The Outbox API from EmailEngine — 1 operation(s) for outbox.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Outbox
  properties:
  - type: OpenAPI
    url: openapi/emailengine-outbox-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-stats-api
  name: EmailEngine Stats API
  description: The Stats API from EmailEngine — 1 operation(s) for stats.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Stats
  properties:
  - type: OpenAPI
    url: openapi/emailengine-stats-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-templates-api
  name: EmailEngine Templates API
  description: The Templates API from EmailEngine — 1 operation(s) for templates.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Templates
  properties:
  - type: OpenAPI
    url: openapi/emailengine-templates-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-tokens-api
  name: EmailEngine Tokens API
  description: The Tokens API from EmailEngine — 1 operation(s) for tokens.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Tokens
  properties:
  - type: OpenAPI
    url: openapi/emailengine-tokens-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
- aid: emailengine:emailengine-webhookroutes-api
  name: EmailEngine Webhookroutes API
  description: The Webhookroutes API from EmailEngine — 1 operation(s) for webhookroutes.
  humanURL: https://emailengine.app/
  baseURL: https://api.emailengine.app
  tags:
  - Webhookroutes
  properties:
  - type: OpenAPI
    url: openapi/emailengine-webhookroutes-api-openapi.yml
  - type: Documentation
    url: https://emailengine.app/
  - type: APIReference
    url: https://learn.emailengine.app/docs/api/emailengine-api
  - type: Documentation
    url: https://learn.emailengine.app/
  - type: SourceCode
    url: https://github.com/postalsys/emailengine
  - type: Webhooks
    url: https://emailengine.app/webhooks
common:
- type: Website
  url: https://www.emailengine.app/
- type: Releases
  url: https://github.com/postalsys/emailengine/releases
- type: SecurityPolicy
  url: https://github.com/postalsys/emailengine/blob/master/SECURITY.md
- type: CodeOfConduct
  url: https://github.com/postalsys/emailengine/blob/master/.github/CODE_OF_CONDUCT.md
- type: ContributionGuide
  url: https://github.com/postalsys/emailengine/blob/master/.github/contributing.md
- type: AgenticAccess
  url: agentic-access/emailengine-agentic-access.yml
- type: DomainSecurity
  url: security/emailengine-domain-security.yml
- name: EmailEngine Documentation
  url: https://learn.emailengine.app/
  type: Documentation
- name: API Reference
  url: https://learn.emailengine.app/docs/api/emailengine-api
  type: APIReference
- name: Webhooks
  url: https://emailengine.app/webhooks
  type: Webhooks
- name: GitHub Repository
  url: https://github.com/postalsys/emailengine
  type: SourceCode
- name: Blog
  url: https://blog.emailengine.app/
  type: Blog
- name: FAQ
  url: https://emailengine.app/#faq
  type: FAQ
- name: Pricing
  url: https://postalsys.com/plans
  type: Pricing
- name: Terms of Service
  url: https://postalsys.com/tos
  type: TermsOfService
- name: Privacy Policy
  url: https://emailengine.app/privacy-policy
  type: PrivacyPolicy
- name: Support
  url: https://emailengine.app/support
  type: Support
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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