Mailsink

Name: Mailsink
Author: heocoi

by heocoiversion 0.1.5i★ –iRuns on your computer

Registry nameio.github.heocoi/mailsink

Install

Overview

Description from the maker (original English)

Disposable inboxes for AI agents and CI: catch the verification email, read the OTP or link.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Chat & email
You need to fill in: MAILSINK_API_KEY

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: MAILSINK_API_KEY, MAILSINK_API_URL

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "mailsink": {
      "command": "npx",
      "args": [
        "-y",
        "@mailsink/mcp"
      ],
      "env": {
        "MAILSINK_API_KEY": "your-value",
        "MAILSINK_API_URL": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add mailsink --env MAILSINK_API_KEY=your-value --env MAILSINK_API_URL=your-value -- npx -y @mailsink/mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "mailsink": {
      "command": "npx",
      "args": [
        "-y",
        "@mailsink/mcp"
      ],
      "env": {
        "MAILSINK_API_KEY": "your-value",
        "MAILSINK_API_URL": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "mailsink": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@mailsink/mcp"
      ],
      "env": {
        "MAILSINK_API_KEY": "your-value",
        "MAILSINK_API_URL": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

MAILSINK_API_KEY secret required env
Your MailSink API key. Get it at https://mailsink.dev/auth/github
MAILSINK_API_URL env
Optional API base URL override (defaults to https://api.mailsink.dev)

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account heocoi, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Chat & emaili

More stars than 0% of the other 1784 servers in this category
Published to the registry more recently than 25% of the other 1784 servers in this category
Basic checks equal to or better than 100% of the other 1784 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Mailsink safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: MAILSINK_API_KEY

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.1.5) reached the registry 3 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: Vexa, emailmd, MCP WhatsApp Cloud

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Vexa

by Vexa-ai

Meeting bot and transcripts for Google Meet, Teams and Zoom. Live or after, speakers labelled.

Runs in the cloud★ 2,949Apache-2.0Updated 2 months ago

Install

emailmd

by anypost

Render markdown into email-safe HTML, lint drafts for deliverability problems, and preview emails.

Computer or cloud★ 1,385MITUpdated 32 days ago

Install

MCP WhatsApp Cloud

by codespar

MCP server for WhatsApp Cloud API (Meta) — messages, media, and templates via Graph API

Runs on your computer★ 277MITUpdated 5 months ago

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

@mailsink/mcp

Model Context Protocol server for MailSink — programmatic temporary email inboxes for AI agents and test automation.

Gives your agent eight typed tools for provisioning disposable addresses, waiting on signup emails, extracting OTP codes and magic links, and cleaning up after itself. Works in Claude Code, Claude Desktop, Cursor, Windsurf, and any other MCP-aware client.

Install

npm install -g @mailsink/mcp

Or run via npx without installing:

npx @mailsink/mcp

Get an API key

Sign in at https://mailsink.dev/app with GitHub.
Copy the key from the one-time reveal. Store it in your password manager or .env.
Export it so the MCP server can read it:

   export MAILSINK_API_KEY="msk_..."

Free tier is 50 inboxes/month and includes MCP. Pro ($15/mo) and Team ($49/mo) lift the inbox cap, raise email size limits, extend TTL, and bump request rates. See pricing.

Configure your client

Claude Code

claude mcp add mailsink -- npx -y @mailsink/mcp

Claude Desktop / Cursor / Windsurf

Add to the mcpServers section of the client's config file:

"mcpServers": { "mailsink": { "command": "npx", "args": ["-y", "@mailsink/mcp"], "env": { "MAILSINK_API_KEY": "msk_..." } } } }

Restart the client. You should see the mailsink server listed with its eight tools.

Tools

Tool	Purpose
`create_inbox`	Provision a throwaway address. Returns `email`, `id`, `expires_at`.
`list_inboxes`	List active inboxes on the account.
`wait_for_email`	Block up to `timeout` seconds (max 120) for any email to arrive.
`get_verification_code`	Extract the most recent OTP from the inbox (polls until found or timeout).
`get_verification_link`	Extract the most recent magic link.
`list_messages`	Summaries of all messages in an inbox.
`get_message`	Full content of a specific message by ID.
`delete_inbox`	Burn an inbox immediately.

Example agent flow

> Sign me up for Figma, capture the verification code, confirm, and

tell me the plan once you're in.

[agent invokes] create_inbox() → agent@codenotify.net [agent fills the Figma signup form with that address] wait_for_email(inbox_id) → blocks 30s… → returns email + OTP [agent types the OTP into the Figma form] delete_inbox(inbox_id) → cleanup

No webhook plumbing. No IMAP credentials. No parsing MIME.

Environment variables

MAILSINK_API_KEY *(required)* — your account's API key.
MAILSINK_API_URL *(optional, default https://api.mailsink.dev)* — override for self-hosted or dev API.

Source

https://github.com/heocoi/mailsink/tree/main/mcp

License

MIT — see LICENSE.

Mailsink

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Chat & emaili

Common questions

Alternatives

Vexa

emailmd

MCP WhatsApp Cloud

README from the maker

@mailsink/mcp

Install

Get an API key

Configure your client

Claude Code

Claude Desktop / Cursor / Windsurf

Tools

Example agent flow

Environment variables

Source

License