SMTP2GO

SMTP2GO is a New Zealand-founded email and SMS delivery platform, running since 2006, that sends and tracks transactional and marketing messages over SMTP relay or a JSON REST API from data centres in the United States, the European Union and Australia. The v3 API covers sending standard, MIME, batch and scheduled email, sending and receiving SMS, verifying sender domains and single sender addresses, managing SMTP users, API keys, IP allow lists and IP authentication, templates, webhooks, suppressions, subaccounts, dedicated IPs and the email archive, plus activity search and delivery statistics. It also ships a remote MCP server and a published Agent Skill for AI agents.

SMTP2GO publishes 11 APIs on the APIs.io network, including Email API, Activity API, API Keys API, and 8 more. Tagged areas include Email, Email Delivery, Transactional Email, SMTP, and SMS.

The SMTP2GO catalog on APIs.io includes 1 event-driven AsyncAPI specification, 1 JSON-LD context, and 1 Spectral governance ruleset.

SMTP2GO’s developer surface includes authentication, documentation, API reference, engineering blog, pricing, support, changelog, and 32 more developer resources.

🌐 Visit website 📡 Source on GitHub

74.1/100 exemplar ▬ flat Agent 52/100 agent ready Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0

AccessFreemiumSelf serve⚡ Free to try

11 APIs 1 MCP Servers

EmailEmail DeliveryTransactional EmailSMTPSMSEmail APIDeliverabilityWebhookMessagingCommunicationsMCPAgent Skills

Kin Score

Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0

Composite quality — 74.1/100 · exemplar

Contract Quality 15.6 / 21

Developer Ergonomics 10.7 / 17

Access Clarity 15.7 / 17

Operational Transparency 8.4 / 11

Contract Governance 4.1 / 10

Discoverability 6.9 / 9

Regulatory Posture 6.3 / 15

Agent readiness — 52/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Regulatory Posture applies to this provider. Its tags matched the Telecommunications 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.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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/smtp2go: 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 11

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

Open Collections 12

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

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Rate Limits 1

Documented rate limits and quota policies.

Smtp2Go Rate Limits

9 limits

RATE LIMITS

FinOps 1

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

JSON Schema 2

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

SMTP2GO Send Email Request

15 properties

JSON SCHEMA

SMTP2GO Suppression

6 properties

JSON SCHEMA

Examples 3

Example request and response payloads for these APIs.

Get Started 5

Portal, sign-up, and the first successful call

Sandbox

DeveloperPortal

GettingStarted

SignUp

Login

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

MCPServer

AgentSkill

LLMsTxt

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

Lifecycle

Conformance

Webhooks

DataModel

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrg

Packages

SDKs

ToolCrosswalk

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Compliance

Compliance

Operate 5

Status, limits, changes, and where to get help

StatusPage

Support

RateLimits

ChangeLog

ChangeLog

Commercial 5

Pricing, plans, and the legal terms of use

Pricing

Plans

FinOps

TermsOfService

PrivacyPolicy

Company 3

The organization behind the API

Website

Website

Blog

Blog

LinkedIn

Other 2

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

name: SMTP2GO
description: SMTP2GO is a New Zealand-founded email and SMS delivery platform, running since 2006, that sends and tracks transactional
  and marketing messages over SMTP relay or a JSON REST API from data centres in the United States, the European Union and
  Australia. The v3 API covers sending standard, MIME, batch and scheduled email, sending and receiving SMS, verifying sender
  domains and single sender addresses, managing SMTP users, API keys, IP allow lists and IP authentication, templates, webhooks,
  suppressions, subaccounts, dedicated IPs and the email archive, plus activity search and delivery statistics. It also ships
  a remote MCP server and a published Agent Skill for AI agents.
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
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/smtp2go.png
url: https://raw.githubusercontent.com/api-evangelist/smtp2go/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-08-13'
specificationVersion: '0.23'
aid: smtp2go
type: Index
tags:
- Email
- Email Delivery
- Transactional Email
- SMTP
- SMS
- Email API
- Deliverability
- Webhook
- Messaging
- Communications
- MCP
- Agent Skills
tags_raw:
- Email
- Email Delivery
- Transactional Email
- SMTP
- SMS
- Email API
- Deliverability
- Webhooks
- Messaging
- Communications
- MCP
- Agent Skills
apis:
- name: SMTP2GO Email API
  description: REST API for sending transactional emails and SMS, managing sender domains, SMTP users, API keys, templates,
    webhooks, suppressions, and accessing delivery reports and activity statistics.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - Email
  - SMS
  - Transactional Email
  - Deliverability
  - SMTP
  - Webhook
  - Templates
  tags_raw:
  - Email
  - SMS
  - Transactional Email
  - Deliverability
  - SMTP
  - Webhooks
  - Templates
  properties:
  - type: Documentation
    url: https://developers.smtp2go.com/docs/introduction-guide
  - type: GettingStarted
    url: https://developers.smtp2go.com/docs/getting-started
  - type: Endpoints
    url: https://developers.smtp2go.com/docs/endpoints
  - type: RateLimits
    url: https://developers.smtp2go.com/docs/rate-limiting
  - type: OpenAPI
    url: https://raw.githubusercontent.com/api-evangelist/smtp2go/refs/heads/main/openapi/smtp2go-email-api-openapi.yml
  - type: OpenAPI
    name: SMTP2GO v3 API (provider-harvested, 73 operations)
    url: openapi/_original/smtp2go-openapi-original.yml
  - type: APIReference
    url: https://developers.smtp2go.com/reference/general-api-resources
  contact:
  - FN: SMTP2GO Support
    url: https://support.smtp2go.com/
- aid: smtp2go:smtp2go-activity-api
  name: SMTP2GO Activity API
  description: Email activity search
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - Activity
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-activity-api-openapi.yml
- aid: smtp2go:smtp2go-api-keys-api
  name: SMTP2GO API Keys API
  description: API key management
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - APIKeys
  tags_raw:
  - API Keys
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-api-keys-api-openapi.yml
- aid: smtp2go:smtp2go-domains-api
  name: SMTP2GO Domains API
  description: Sender domain management
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - Domains
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-domains-api-openapi.yml
- aid: smtp2go:smtp2go-sms-api
  name: SMTP2GO SMS API
  description: Send and receive SMS messages
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - SMS
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-sms-api-openapi.yml
- aid: smtp2go:smtp2go-smtp-users-api
  name: SMTP2GO SMTP Users API
  description: SMTP user account management
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - SMTP Users
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-smtp-users-api-openapi.yml
- aid: smtp2go:smtp2go-stats-api
  name: SMTP2GO Stats API
  description: Email delivery statistics and reports
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - Stats
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-stats-api-openapi.yml
- aid: smtp2go:smtp2go-subaccounts-api
  name: SMTP2GO Subaccounts API
  description: Subaccount management
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - Subaccounts
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-subaccounts-api-openapi.yml
- aid: smtp2go:smtp2go-suppressions-api
  name: SMTP2GO Suppressions API
  description: Suppression list management
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - Suppressions
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-suppressions-api-openapi.yml
- aid: smtp2go:smtp2go-templates-api
  name: SMTP2GO Templates API
  description: Email template management
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - Templates
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-templates-api-openapi.yml
- aid: smtp2go:smtp2go-webhooks-api
  name: SMTP2GO Webhooks API
  description: Webhook configuration
  humanURL: https://developers.smtp2go.com/docs/introduction-guide
  baseURL: https://api.smtp2go.com/v3
  tags:
  - Webhook
  tags_raw:
  - Webhooks
  properties:
  - type: OpenAPI
    url: openapi/smtp2go-webhooks-api-openapi.yml
common:
- type: AgenticAccess
  url: agentic-access/smtp2go-agentic-access.yml
- type: DomainSecurity
  url: security/smtp2go-domain-security.yml
- type: Authentication
  url: authentication/smtp2go-authentication.yml
- type: Website
  url: https://www.smtp2go.com/
- type: Documentation
  url: https://developers.smtp2go.com/docs/introduction-guide
- type: APIReference
  url: https://developers.smtp2go.com/reference/general-api-resources
- type: GitHubOrg
  url: https://github.com/smtp2go-oss
- type: Blog
  url: https://www.smtp2go.com/blog/
- type: Pricing
  url: https://www.smtp2go.com/pricing/
- type: StatusPage
  url: https://smtp2gostatus.com/
- type: LinkedIn
  url: https://www.linkedin.com/company/smtp2go
- type: X
  url: https://x.com/smtp2go
- type: Support
  url: https://support.smtp2go.com/
- type: Plans
  url: plans/smtp2go-plans-pricing.yml
- type: RateLimits
  url: rate-limits/smtp2go-rate-limits.yml
- type: FinOps
  url: finops/smtp2go-finops.yml
- type: Packages
  name: SMTP2GO client libraries
  url: packages/smtp2go-packages.yml
- type: SDKs
  name: SMTP2GO official SDKs
  url: packages/smtp2go-packages.yml
- type: MCPServer
  name: SMTP2GO remote MCP server
  url: mcp/smtp2go-mcp.yml
- type: ToolCrosswalk
  name: SMTP2GO MCP tool to REST operation crosswalk
  url: mcp/smtp2go-tool-crosswalk.yml
- type: AgentSkill
  name: SMTP2GO Agent Skills
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/smtp2go-llms.txt
- type: Overlay
  url: overlays/smtp2go-api-overlay.yaml
- type: Conventions
  url: conventions/smtp2go-conventions.yml
- type: ErrorCatalog
  url: errors/smtp2go-problem-types.yml
- type: Lifecycle
  url: lifecycle/smtp2go-lifecycle.yml
- type: ChangeLog
  url: changelog/smtp2go-changelog.yml
- type: ChangeLog
  name: SMTP2GO API changelog
  url: https://developers.smtp2go.com/reference/changelog
- type: Conformance
  url: conformance/smtp2go-conformance.yml
- type: Compliance
  name: Security and Privacy at SMTP2GO
  url: https://www.smtp2go.com/blog/security-and-privacy-at-smtp2go/
- type: Webhooks
  name: SMTP2GO webhook event surface
  url: asyncapi/smtp2go-webhooks.yml
- type: Sandbox
  name: SMTP2GO Sandbox Mode
  url: sandbox/smtp2go-sandbox.yml
- type: DataModel
  url: data-model/smtp2go-data-model.yml
- type: DeveloperPortal
  url: https://developers.smtp2go.com/
- type: GettingStarted
  url: https://developers.smtp2go.com/docs/getting-started
- type: SignUp
  url: https://www.smtp2go.com/pricing/signup/
- type: Login
  url: https://app.smtp2go.com/login/
- type: TermsOfService
  url: https://www.smtp2go.com/terms/
- type: PrivacyPolicy
  url: https://www.smtp2go.com/privacy/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 21
  pass: local-v1