Maileroo

Maileroo provides transactional and marketing email delivery via a developer-friendly REST API with high deliverability, SMTP relay support, email tracking, and SDKs for popular programming languages. Trusted by businesses of all sizes to handle millions of emails every month.

Maileroo publishes 2 API contracts indexed on the APIs.io network: Emails API and Scheduled API. Tagged areas include Email, Email Delivery, Marketing Email, SMTP, and Transactional Email.

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

Maileroo’s developer surface includes authentication, developer portal, documentation, signup flow, pricing, engineering blog, and 10 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

36.1/100 thin ▬ flat Agent 25/100 agent aware Front door AI 1/6 silent Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract

Email Email Delivery Marketing Email SMTP Transactional Email

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 36.1/100 · thin

Contract Quality 9.8 / 19

Developer Ergonomics 7.1 / 15

Access Clarity 3.8 / 15

Operational Transparency 1.2 / 10

Contract Governance 1.2 / 9

Discoverability 5.5 / 8

Regulatory Posture 0.9 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 25/100 · 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 8 / 8

Request/Response Examples 0 / 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

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 Ask about this →
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) Ask about this →
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link Ask about this →
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document Ask about this →
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented) Ask about this →

8 more unmet checks in the Agent Readiness table above.

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

Access Clarity scores 25.5 — up to +14.9 composite points Ask about this →
Contract Quality scores 52.3 — up to +11.9 composite points Ask about this →
Operational Transparency scores 11.9 — up to +11.5 composite points Ask about this →

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.

Not sure how this applies to your stack? Ask about any one item. Kin Lane reads every question, looks at your profile and your situation, and replies with what a fix would take — scoped to that one area, priced up front, yours whether you ship it or not. Ask a question →

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/maileroo/apis.yml: open an issue on github.com/api-evangelist/maileroo 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 2

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

Maileroo Emails API

Send transactional and bulk emails

Maileroo Scheduled API

Manage scheduled email deliveries

Open Collections 3

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

Maileroo Email API

OPEN COLLECTION

Maileroo Email Emails API

OPEN COLLECTION

Maileroo Email Emails Scheduled API

OPEN COLLECTION

Maileroo API pricing

Not yet checked against Maileroo's own pricing page. Compiled by API Evangelist on 2026-05-04; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free freemium	Free
Professional paid	Free
Enterprise enterprise	—

Plan details, limits and sources →

Rate limits

Free Tier Default: 10 requests per minute
Free Tier Monthly Quota: 1000 requests per month
Professional Tier Default: 100 requests per minute

Compiled by API Evangelist, not yet checked against Maileroo's documentation. All 5 limits →

Pricing Plans 1

Published pricing tiers and plan structures.

Maileroo Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Maileroo Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Maileroo Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs. Counts are the severity each rule declares, not results of running them.

Maileroo API Rules

59 rules · 56 error-severity 2 warn-severity 1 info-severity

SPECTRAL

Security Posture 2

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

Maileroo Authentication

apiKey/http · 2 schemes

SECURITY

Maileroo Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access (API Evangelist recommendations) 1

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

Maileroo Agentic Access

5 operations · 4 acting

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

Portal

Portal

Signup

Signup

Login

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LlmsText

LlmsText

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Pricing

Pricing

Company 3

The organization behind the API

Website

Website

LinkedIn

Blog

Blog

Source (apis.yml)

aid: maileroo
name: Maileroo
description: Maileroo provides transactional and marketing email delivery via a developer-friendly REST API with high deliverability,
  SMTP relay support, email tracking, and SDKs for popular programming languages. Trusted by businesses of all sizes to handle
  millions of emails every month.
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: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-13'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/maileroo.png
tags:
- Email
- Email Delivery
- Marketing Email
- SMTP
- Transactional Email
url: https://raw.githubusercontent.com/api-evangelist/maileroo/refs/heads/main/apis.yml
created: '2025-02-06'
modified: '2026-05-19'
specificationVersion: '0.23'
apis:
- aid: maileroo:maileroo-emails-api
  name: Maileroo Emails API
  description: Send transactional and bulk emails
  humanURL: https://maileroo.com/email-for-developers
  baseURL: https://smtp.maileroo.com
  tags:
  - Email
  tags_raw:
  - Emails
  properties:
  - type: OpenAPI
    url: openapi/maileroo-emails-api-openapi.yml
  - type: Documentation
    url: https://maileroo.com/docs/email-api/introduction/
  - type: GettingStarted
    url: https://maileroo.com/docs/introduction/
  - type: Reference
    url: https://maileroo.com/docs/email-api/send-basic-email/
  - type: SDKs
    url: https://maileroo.com/docs/email-api/libraries-and-sdks/
- aid: maileroo:maileroo-scheduled-api
  name: Maileroo Scheduled API
  description: Manage scheduled email deliveries
  humanURL: https://maileroo.com/email-for-developers
  baseURL: https://smtp.maileroo.com
  tags:
  - Scheduled
  properties:
  - type: OpenAPI
    url: openapi/maileroo-scheduled-api-openapi.yml
  - type: Documentation
    url: https://maileroo.com/docs/email-api/introduction/
  - type: GettingStarted
    url: https://maileroo.com/docs/introduction/
  - type: Reference
    url: https://maileroo.com/docs/email-api/send-basic-email/
  - type: SDKs
    url: https://maileroo.com/docs/email-api/libraries-and-sdks/
common:
- type: Plans
  url: plans/maileroo-plans-pricing.yml
- type: RateLimits
  url: rate-limits/maileroo-rate-limits.yml
- type: FinOps
  url: finops/maileroo-finops.yml
- type: Website
  url: https://www.maileroo.com/
- type: AgenticAccess
  url: agentic-access/maileroo-agentic-access.yml
- type: DomainSecurity
  url: security/maileroo-domain-security.yml
- type: Authentication
  url: authentication/maileroo-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/maileroo
- type: Portal
  url: https://maileroo.com/email-for-developers
- type: Documentation
  url: https://maileroo.com/docs/
- type: Signup
  url: https://app.maileroo.com/register
- type: Login
  url: https://app.maileroo.com/login
- type: GitHubOrganization
  url: https://github.com/maileroo
- type: Pricing
  url: https://maileroo.com/pricing
- type: LlmsText
  url: https://maileroo.com/llms.txt
- type: Blog
  url: https://maileroo.com/blog/feed
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Maileroo API — frequently asked questions

Does Maileroo have an API?

Yes. APIs.io lists 2 APIs from Maileroo, including Maileroo Emails API and Maileroo Scheduled API.

Is there an OpenAPI specification for the Maileroo API?

Yes. APIs.io indexes 2 OpenAPI specifications for Maileroo, each linked for download from this page.

How do I authenticate with the Maileroo API?

Maileroo uses bearer-token authentication (apiKey/http · 2 schemes). The details are profiled on APIs.io as Maileroo Authentication.

How much does the Maileroo API cost?

APIs.io lists 3 pricing plans for Maileroo, with each plan's price, limits and inclusions under Pricing on this page.

Is the Maileroo API ready for AI agents?

Maileroo has a Kin Score of 36.1 out of 100 (thin) and an Agent Readiness score of 25.3 (agent-aware), scored by API Evangelist on 2026-11-13.

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