Apache James

Apache James (Java Apache Mail Enterprise Server) is a portable and enterprise-ready mail server built entirely in Java. It implements SMTP, IMAP, POP3, and JMAP protocols and provides a modular architecture with a comprehensive administration REST API and Cassandra-backed distributed deployment.

Apache James publishes 8 APIs on the APIs.io network, including Domains API, HealthCheck API, Mailboxes API, and 5 more. Tagged areas include Email, IMAP, Java, JMAP, and Mail Server.

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

Apache James’ developer surface includes authentication, documentation, getting-started guide, engineering blog, and 9 more developer resources.

🌐 Visit website 📡 Source on GitHub

53.9/100 developing ▼ -5.1 Agent 37/100 agent ready Full breakdown ↓
scored 2026-07-28 · rubric v0.6

AccessFreemiumSelf serve⚡ Free to try

9 APIs 8 Features 4 Use Cases

EmailIMAPJavaJMAPMail ServerOpen SourceSMTP

Kin Score

Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6

Composite quality — 53.9/100 · developing

Contract Quality 15.8 / 25

Developer Ergonomics 6.5 / 20

Commercial Clarity 10.0 / 20

Operational Transparency 6.8 / 13

Governance 8.3 / 12

Discoverability 6.5 / 10

Agent readiness — 37/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 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

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/apache-james: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 9

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

Rate Limits 1

Documented rate limits and quota policies.

Apache James Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Apache James Finops

FINOPS

Features 8

Notable capabilities this provider offers.

SMTP Server

Full SMTP server implementation with TLS, DKIM, SPF, and DMARC support.

IMAP Server

IMAP4 server with full RFC compliance for email client access.

JMAP Support

Modern JMAP protocol implementation for efficient email synchronization.

WebAdmin REST API

HTTP REST API for complete server administration without downtime.

Distributed Architecture

Cassandra-backed distributed deployment for high availability.

Modular Design

Pluggable architecture supporting custom protocols, storage, and authentication.

Mail Queuing

Persistent mail queuing with configurable retry strategies.

Quota Management

Per-user, per-domain, and global mailbox and message quota enforcement.

Scroll for all 8

JSON Schema 9

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

Scroll for all 9

Examples 9

Example request and response payloads for these APIs.

Scroll for all 9

Use Cases 4

What developers build with this provider.

Enterprise Mail Server

Deploy a full-featured enterprise mail server with SMTP, IMAP, and JMAP.

Mail Server Migration

Migrate from other mail servers with full protocol compatibility.

Automated Email Processing

Build automated email pipelines using James mailet and matcher APIs.

High-Availability Mail

Deploy distributed James clusters with Cassandra and RabbitMQ for HA.

Integrations 5

Pre-built integrations with other platforms and tools.

Apache Cassandra

Distributed mail storage backend for high availability deployments.

Apache Kafka

Event bus integration for distributed James deployments.

RabbitMQ

AMQP message queue for inter-node communication.

Elasticsearch/OpenSearch

Full-text mail search indexing via Elasticsearch integration.

OpenLDAP

LDAP authentication and directory integration for user management.

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Versioning

Versioning

SpectralRules

SpectralRules

Vocabulary

Vocabulary

Build 2

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

GitHubRepository

GitHubRepository

Access & Security 3

Authentication, authorization, and security posture

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Authentication

Authentication

Commercial 1

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

Company 1

The organization behind the API

Blog

Blog

Source (apis.yml)

aid: apache-james
name: Apache James
description: Apache James (Java Apache Mail Enterprise Server) is a portable and enterprise-ready mail server built entirely
  in Java. It implements SMTP, IMAP, POP3, and JMAP protocols and provides a modular architecture with a comprehensive administration
  REST API and Cassandra-backed distributed deployment.
type: Index
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
position: Consumer
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/apache-james.png
tags:
- Email
- IMAP
- Java
- JMAP
- Mail Server
- Open Source
- SMTP
created: '2026-03-16'
modified: '2026-05-19'
url: https://raw.githubusercontent.com/api-evangelist/apache-james/refs/heads/main/apis.yml
specificationVersion: '0.19'
apis:
- aid: apache-james:jmap-api
  name: Apache James JMAP API
  description: The JMAP (JSON Meta Application Protocol) implementation in James provides a modern, efficient email protocol
    for synchronizing messages, mailboxes, contacts, and calendars for email clients.
  humanURL: https://james.apache.org/server/rfcs-compliance.html
  tags:
  - Email
  - JMAP
  - JSON
  properties:
  - type: Documentation
    url: https://james.apache.org/server/rfcs-compliance.html
- aid: apache-james:apache-james-domains-api
  name: Apache James Domains API
  description: Email domain management
  humanURL: https://james.apache.org/server/manage-webadmin.html
  tags:
  - Domains
  properties:
  - type: OpenAPI
    url: openapi/apache-james-domains-api-openapi.yml
  - type: Documentation
    url: https://james.apache.org/server/manage-webadmin.html
- aid: apache-james:apache-james-healthcheck-api
  name: Apache James HealthCheck API
  description: System health monitoring
  humanURL: https://james.apache.org/server/manage-webadmin.html
  tags:
  - HealthCheck
  properties:
  - type: OpenAPI
    url: openapi/apache-james-healthcheck-api-openapi.yml
  - type: Documentation
    url: https://james.apache.org/server/manage-webadmin.html
- aid: apache-james:apache-james-mailboxes-api
  name: Apache James Mailboxes API
  description: Mailbox management
  humanURL: https://james.apache.org/server/manage-webadmin.html
  tags:
  - Mailboxes
  properties:
  - type: OpenAPI
    url: openapi/apache-james-mailboxes-api-openapi.yml
  - type: Documentation
    url: https://james.apache.org/server/manage-webadmin.html
- aid: apache-james:apache-james-mailqueues-api
  name: Apache James MailQueues API
  description: Mail queue management
  humanURL: https://james.apache.org/server/manage-webadmin.html
  tags:
  - MailQueues
  properties:
  - type: OpenAPI
    url: openapi/apache-james-mailqueues-api-openapi.yml
  - type: Documentation
    url: https://james.apache.org/server/manage-webadmin.html
- aid: apache-james:apache-james-mailrepositories-api
  name: Apache James MailRepositories API
  description: Mail repository management
  humanURL: https://james.apache.org/server/manage-webadmin.html
  tags:
  - MailRepositories
  properties:
  - type: OpenAPI
    url: openapi/apache-james-mailrepositories-api-openapi.yml
  - type: Documentation
    url: https://james.apache.org/server/manage-webadmin.html
- aid: apache-james:apache-james-quotas-api
  name: Apache James Quotas API
  description: Storage and message quota management
  humanURL: https://james.apache.org/server/manage-webadmin.html
  tags:
  - Quotas
  properties:
  - type: OpenAPI
    url: openapi/apache-james-quotas-api-openapi.yml
  - type: Documentation
    url: https://james.apache.org/server/manage-webadmin.html
- aid: apache-james:apache-james-tasks-api
  name: Apache James Tasks API
  description: Asynchronous task management
  humanURL: https://james.apache.org/server/manage-webadmin.html
  tags:
  - Tasks
  properties:
  - type: OpenAPI
    url: openapi/apache-james-tasks-api-openapi.yml
  - type: Documentation
    url: https://james.apache.org/server/manage-webadmin.html
- aid: apache-james:apache-james-users-api
  name: Apache James Users API
  description: User account management
  humanURL: https://james.apache.org/server/manage-webadmin.html
  tags:
  - Users
  properties:
  - type: OpenAPI
    url: openapi/apache-james-users-api-openapi.yml
  - type: Documentation
    url: https://james.apache.org/server/manage-webadmin.html
common:
- type: AgenticAccess
  url: agentic-access/apache-james-agentic-access.yml
- type: VulnerabilityDisclosure
  url: security/apache-james-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/apache-james-domain-security.yml
- type: Authentication
  url: authentication/apache-james-authentication.yml
- type: GitHubOrganization
  url: https://github.com/apache
- type: GitHubRepository
  url: https://github.com/apache/james-project
- type: Documentation
  url: https://james.apache.org/documentation.html
- type: GettingStarted
  url: https://james.apache.org/server/quick-start.html
- type: TermsOfService
  url: https://www.apache.org/licenses/LICENSE-2.0
- type: Blog
  url: https://james.apache.org/blog/
- type: Versioning
  url: https://james.apache.org/download.cgi
- type: SpectralRules
  url: rules/apache-james-spectral-rules.yml
- type: Vocabulary
  url: vocabulary/apache-james-vocabulary.yaml
- type: Features
  data:
  - name: SMTP Server
    description: Full SMTP server implementation with TLS, DKIM, SPF, and DMARC support.
  - name: IMAP Server
    description: IMAP4 server with full RFC compliance for email client access.
  - name: JMAP Support
    description: Modern JMAP protocol implementation for efficient email synchronization.
  - name: WebAdmin REST API
    description: HTTP REST API for complete server administration without downtime.
  - name: Distributed Architecture
    description: Cassandra-backed distributed deployment for high availability.
  - name: Modular Design
    description: Pluggable architecture supporting custom protocols, storage, and authentication.
  - name: Mail Queuing
    description: Persistent mail queuing with configurable retry strategies.
  - name: Quota Management
    description: Per-user, per-domain, and global mailbox and message quota enforcement.
- type: UseCases
  data:
  - name: Enterprise Mail Server
    description: Deploy a full-featured enterprise mail server with SMTP, IMAP, and JMAP.
  - name: Mail Server Migration
    description: Migrate from other mail servers with full protocol compatibility.
  - name: Automated Email Processing
    description: Build automated email pipelines using James mailet and matcher APIs.
  - name: High-Availability Mail
    description: Deploy distributed James clusters with Cassandra and RabbitMQ for HA.
- type: Integrations
  data:
  - name: Apache Cassandra
    description: Distributed mail storage backend for high availability deployments.
  - name: Apache Kafka
    description: Event bus integration for distributed James deployments.
  - name: RabbitMQ
    description: AMQP message queue for inter-node communication.
  - name: Elasticsearch/OpenSearch
    description: Full-text mail search indexing via Elasticsearch integration.
  - name: OpenLDAP
    description: LDAP authentication and directory integration for user management.
maintainers:
- FN: Kin Lane
  email: info@apievangelist.com