MailCue is an open-source project built for developers, QA engineers, and DevOps teams.

Does MailCue have a free plan?

Yes — MailCue is open source under the MIT license and free to use.

What platforms does MailCue run on?

MailCue runs on the web, the command line, and API. It can also be self-hosted.

Is MailCue still active?

The GitHub repository shows 212 commits in the last 90 days.

Who develops MailCue?

MailCue is developed by olib-ai.

Is MailCue open source?

Yes — MailCue is open source under the MIT license, developed on GitHub.

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MailCue

Name: MailCue
Author: olib-ai

github.ioInfrastructure

MailCue is an open-source email testing and mail server stack distributed as a Docker container. It combines SMTP, IMAP, POP3, DKIM, DMARC, SPF, spam filtering, GPG/PGP-MIME, a REST API, SDKs, and an MCP server for developers and QA teams.

Open SourceMITWebCLISelf-hostedAPI

Visit github.io

22stars

3forks

12features

2026since

Overview

12 features

MailCue is a Messaging, queues & streaming project. It focuses on testing and operating realistic email infrastructure without assembling and configuring multiple mail services. It is built as an open-source project for developers, QA engineers, and DevOps teams. MailCue is open source under the MIT license. It runs on the web, the command line, and API, and it can be self-hosted.

Behind MailCue is olib-ai, and it first shipped in 2026. The project is developed in the open on GitHub with 22 stars and 212 commits in the last 90 days. Among its 12 catalogued features are Catch-all SMTP, IMAP and POP3, and DKIM signing. It exposes integrations via an MCP server and a public API.

Summary written by a language model from the project’s public pages.

Catch-all SMTP
IMAP and POP3
DKIM signing
DMARC verification
SPF checks
Spam filtering
GPG/PGP-MIME
REST API
Python SDK
Node SDK
MCP server
Web UI

Built with & integrations

Connectors

MCPAPI

Runs on

BrowserCLISelf-hostedAPI-only

Trust & compliance

License

MIT

Verified signals

HTTPSOpen SourceFree tierGitHub · ★ 22Active maintenance

Indexing history

What PulseGate has recorded for this listing

Indexed23 Aug · 10:04 UTC
Mailcue verified against its public source
Source: PulseGate · Open

Frequently asked questions about MailCue

What is MailCue?: MailCue focuses on testing and operating realistic email infrastructure without assembling and configuring multiple mail services. It is catalogued under Messaging, queues & streaming on PulseGate.
Who is MailCue for?: MailCue is an open-source project built for developers, QA engineers, and DevOps teams.
Does MailCue have a free plan?: Yes — MailCue is open source under the MIT license and free to use.
What platforms does MailCue run on?: MailCue runs on the web, the command line, and API. It can also be self-hosted.
Is MailCue still active?: The GitHub repository shows 212 commits in the last 90 days.
Who develops MailCue?: MailCue is developed by olib-ai.
When did MailCue launch?: MailCue first shipped in 2026.
Is MailCue open source?: Yes — MailCue is open source under the MIT license, developed on GitHub.

At a glance

Pricing: Open Source
Platforms: Api · Cli · Web
Languages: English
Open source: Yes · ★ 22
License: MIT
First seen: 23 Aug 2026
Built for: developers, QA engineers, and DevOps teams
Model: Open source
Solves: Testing and operating realistic email infrastructure without assembling and configuring multiple mail services.

Registered as

GitHub: Olib-AI/mailcue

Developer

olib-ai

Small team

GitHub

Open source

View on GitHub

Stars: 22
Forks: 3
Open issues: 9
Last commit: 22 Aug 2026
Commits 90d: 212
Contributors: 2
Authorship: Small team
Default branch: main
Latest release: tunnel-v0.3.0 · 20 Aug 2026

Index record

Indexed: 23 Aug 2026
Lifecycle: Alive
First seen: Aug 2026
Last seen: 23 Aug 2026

Identity audit (13)

Slug: mailcue-github-io
Lifecycle state recorded: 23 Aug 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 23 Aug 2026
Timeline basis: Indexed-at chronology (no inferred launch/funding milestones).
Name from: Derived from the project's own page and URL.
Category from: Assigned by a language model.
Summary from: Written by a language model from public pages.
Languages from: Detected by a language model, checked against the page's own declaration.
Last updated: 23 Aug 2026
Canonical URL: https://olib-ai.github.io/mailcue

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