MailProbe

Name: MailProbe
Author: mailprobe

by mailprobeversion 1.1.2i★ –iComputer or cloud

Registry namedev.mailprobe/mailprobe

Install

Overview

Description from the maker (original English)

Verify email addresses in real time: deliverability, disposable and role addresses, typo fixes.

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: Computer or cloud
Transport: stdio, Streamable HTTP
Category: Chat & email
You need to fill in: MAILPROBE_API_KEY, Authorization

Install

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

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
You fill in yourself: MAILPROBE_API_KEY, Authorization

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

You need

Runs in the cloudNothing to install; it connects over the internet
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 …”.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Or run it on your computer

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

{
  "mcpServers": {
    "mailprobe": {
      "command": "npx",
      "args": [
        "-y",
        "mailprobe-mcp"
      ],
      "env": {
        "MAILPROBE_API_KEY": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add --transport http mailprobe https://mailprobe.dev/mcp --header 'Authorization: Bearer {api_key}'

Or run it on your computer

claude mcp add mailprobe --env MAILPROBE_API_KEY=your-value -- npx -y mailprobe-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": {
    "mailprobe": {
      "url": "https://mailprobe.dev/mcp",
      "headers": {
        "Authorization": "Bearer {api_key}"
      }
    }
  }
}

Or run it on your computer

Open in Cursor

Or copy the settings yourself

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

{
  "mcpServers": {
    "mailprobe": {
      "command": "npx",
      "args": [
        "-y",
        "mailprobe-mcp"
      ],
      "env": {
        "MAILPROBE_API_KEY": "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": {
    "mailprobe": {
      "type": "http",
      "url": "https://mailprobe.dev/mcp",
      "headers": {
        "Authorization": "Bearer {api_key}"
      }
    }
  }
}

Or run it on your computer

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "mailprobe": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mailprobe-mcp"
      ],
      "env": {
        "MAILPROBE_API_KEY": "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 address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

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

Values you fill in

MAILPROBE_API_KEY secret required env
MailProbe API key, which starts with mp_live_, created under Developer in your account
Authorization secret required HTTP header
Your MailProbe API key, created under Developer in your account

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

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

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 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified against the domain mailprobe.dev (the registry checks domain ownership)
… 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 checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Chat & emaili

More stars than 0% of the other 1763 servers in this category
Published to the registry more recently than 87% of the other 1763 servers in this category
Basic checks equal to or better than 100% of the other 1763 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 MailProbe 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: MAILPROBE_API_KEY, Authorization

Does it run on my computer or in the cloud?

Either way works: install it on your computer or connect to the cloud version.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.1.2) reached the registry 3 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

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 31 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.

mailprobe-mcp

Official Model Context Protocol server of the MailProbe API. Your AI assistant checks whether email addresses exist and can receive mail, in real time and without sending anything: one address, or a list before a campaign. Verification runs on OVHcloud servers in France, and the API stores no address.

Installation · Tools · How it behaves · Development

There are two ways to reach it, with the same two tools:

the remote server that MailProbe runs at https://mailprobe.dev/mcp, for a client that connects to a remote server and can send a header: nothing to install;
the local server of this package, npx -y mailprobe-mcp, for a client that starts its servers on your computer.

This repository also holds the Claude Code plugin and the skill that tells an assistant how to read a result and how to go through a list.

Installation

Create an account on mailprobe.dev. It comes with 100 free credits; see pricing for more.
Create an API key, which starts with mp_live_, under Developer in your account. MailProbe shows it only once, at creation.
Add one of the two servers to your MCP client.

Remote server

The key goes in the Authorization header. In Claude Code:

claude mcp add --transport http mailprobe https://mailprobe.dev/mcp --header "Authorization: Bearer mp_live_..."

In Cursor, in .cursor/mcp.json:

"mcpServers": { "mailprobe": { "url": "https://mailprobe.dev/mcp", "headers": { "Authorization": "Bearer mp_live_..." } } } }

Any other client that connects to a remote MCP server and can send a header works the same way.

Local server

The key goes in the MAILPROBE_API_KEY environment variable, and the server needs Node.js 22 or later. In Claude Desktop and the other clients configured with a JSON file:

"mcpServers": { "mailprobe": { "command": "npx", "args": ["-y", "mailprobe-mcp"], "env": { "MAILPROBE_API_KEY": "mp_live_..." } } } }

The Claude and ChatGPT apps connect to a remote server only through an OAuth sign-in, which MailProbe does not offer yet. Claude Desktop takes the local server above; elsewhere, MailProbe is available through Zapier MCP.

Claude Code plugin

The plugin connects Claude Code to the remote server and adds a skill that tells the assistant how to read a result, what a call costs, and how to go through a list.

/plugin marketplace add mailprobe/mcp

/plugin install mailprobe@mailprobe

Claude Code asks for the API key when the plugin is enabled, and keeps it in the credential store of the system, not in a settings file. To set it later, run /plugin configure mailprobe@mailprobe, or open /plugin, Installed tab, mailprobe, Configure options. A remote server you added by hand at the same address takes precedence over the one of the plugin.

For another agent that loads SKILL.md skills, add one of the two servers above and take the skill alone: plugin/skills/mailprobe/SKILL.md in this repository, also listed on Agensi.

Then ask for what you need: "does jane@example.com exist?", "check the addresses of contacts.csv before I send the newsletter", "which of these sign-ups are disposable?".

Tools

Tool	What it does
`verify_emails`	Verifies 1 to 20 addresses and returns one result per address, in the order given: `status` (`valid`, `invalid`, `risky` or `unknown`), a `score` from 0 to 100, the `reason` of a verdict that is not plainly deliverable, the `disposable`, `role_based`, `free_provider` and `catch_all` flags, and `did_you_mean` for a likely typo
`get_credits`	Returns the credits left on the account of the API key

The fields of a result are those of the API: see the API documentation.

How it behaves

Nothing is sent to the address. MailProbe checks the syntax, the mail servers of the domain, then asks the mail server whether the mailbox exists, and stops there.
Nothing is stored. An address verified through the API is processed in memory and gone when the response is sent. No result is reused for a later request.
The same tools on both servers. The local server carries the instructions and the tool definitions of the remote one, word for word, and words a refusal the same way. It adds nothing between the assistant and the API: it sends the addresses to https://mailprobe.dev/api/v1 and returns the answer.
Credits. One credit per address actually probed, taken from your account as with the API. An address repeated in the same call, an entry that is not a well-formed address, an address that has no verdict yet when the call answers and one whose server refused the connection cost nothing. get_credits is free.
Rate limit. The API accepts 60 calls per minute for an API key, and a call of 20 addresses counts as one. A refused call gives the number of seconds to wait. The local server waits by itself and tries again, twice at most, only for delays of 30 seconds or less and only while the call can still answer in time; otherwise the assistant gets the delay to wait.
Response time. A call answers within about 55 seconds, on both servers, because MCP clients give up on a tool call after a minute. An address that has no verdict yet at that point comes back unknown with the reason timeout, at no charge: send it again.
Long lists. A call takes 20 addresses, so an assistant sends a list in several calls. Above a few hundred addresses, the batch screen of your account is the right tool: a pasted list of up to 500 addresses, or a CSV or TXT file of up to 250,000, verified in the background.
Errors. A refusal comes back to the assistant as a sentence it can act on: the key to set, the credits to buy, the delay to wait.
Without a key. The local server starts and lists its tools; a call explains how to set MAILPROBE_API_KEY.

Every request of the local server carries User-Agent: mailprobe-mcp/ . Mention it when you contact support: it tells your calls apart in the API's logs.

Development

The local server has no dependency: Node.js runs the sources as they are. It talks to its client over stdio and serves both eras of the protocol from the same process: revision 2026-07-28, where each request carries its protocol version, and the earlier revisions (2025-11-25 down to 2024-11-05), which start with an initialize handshake.

npm test

runs the tests against a fake MailProbe API on a local port: no key and no network are needed. They also check that the package, the plugin, the skill and this README agree.

npm run check-tools

compares the instructions and the tool definitions of this package with those of the remote server, which gives them without a key.

Plugin

plugin/ holds the Claude Code plugin: its manifest, the .mcp.json that points at the remote server, and the skill, plugin/skills/mailprobe/SKILL.md. .claude-plugin/marketplace.json is the catalog that lets Claude Code install the plugin from this repository. Neither is part of the npm package.

claude plugin validate . --strict

claude --plugin-dir ./plugin

check the manifests, then start a session with the plugin loaded from the folder, without installing it. A user gets a change of the plugin or of the skill when the version changes: it ships with a release.

Releasing

Set the version in package.json and plugin/.claude-plugin/plugin.json, and date its section in CHANGELOG.md.
Run npm test and npm run check-tools.
Commit, then push a tag named after the version: the Publish workflow publishes the package to npm through Trusted Publishing, with a provenance statement.
When the skill changed, upload it again to its Agensi listing, as a new version: a ZIP of a mailprobe/ folder that holds the SKILL.md. Nothing updates the listing from this repository.

Resources

Support

Open an issue or write to contact@mailprobe.dev.

License

MIT, see LICENSE.

MailProbe

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Or run it on your computer

Or run it on your computer

Or run it on your computer

Or run it on your computer

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

mailprobe-mcp

Installation

Remote server

Local server

Claude Code plugin

Tools

How it behaves

Development

Plugin

Releasing

Resources

Support

License