MX Probe

Name: MX Probe
Author: andrewchmr

by andrewchmrversion 0.2.8i★ 2 (Stars for the whole repo)iRuns on your computer

Registry namedev.mxprobe/mxprobe

How to install

What it does

Email verification for AI agents: send, hold or kill with the reason. Signup and credits by API.

Connects Runs on your computer
Account or key Needs MXPROBE_API_KEY
Category Chat & email

Install

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

Passed 3/3 checks · Runs on your computer · ✓ Commands checked Nov 13, 2026

First: which AI do you use?

ClaudeWeb · app · phoneChatGPTWebClaude CodeTerminalCursorCode editorVS CodeCode editorOtherOther apps

Pick your app and the steps appear below.

Works with Claude, with some setup first

You need a MX Probe key (create it on the maker’s site) · Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone

Let AI install it

Copy this message into a Claude chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server MX Probe for Claude on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "mcpServers": { "mxprobe": { "command": "npx", "args": [ "-y", "mxprobe", "mcp" ], "env": { "MXPROBE_API_KEY": "your-value" } } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) For MXPROBE_API_KEY, leave "your-value" in place and tell me to paste the real value myself into the file or the app’s field. Never ask me to type a key in chat. 5) Do what we agreed, then check that the MX Probe tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Sign up and create a MX Probe key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the MX Probe site ↗
Done
Open the Claude desktop app’s settings file
SettingsDeveloperEdit Config
Done

Paste these settings and save the file

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

Paste the key only into the app’s field, never into a chat or to anyone

Done

Quit Claude and open it again
Done
Try it
Use MX Probe and tell me what you can do for me, then show me one thing
✓ If Claude says it is using MX Probe or shows a MX Probe tool in the answer, you are connected

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

ChatGPT cannot connect MX Probe yet

MX Probe runs on your computer, but ChatGPT can only connect servers that run on the web

What you can do instead

A · Use an app that can connect MX Probe

Steps for Claude →You need a MX Probe key (create it on the maker’s site) · Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone
Steps for Claude Code →You need a MX Probe key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Steps for Cursor →You need a MX Probe key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Steps for VS Code →You need a MX Probe key (create it on the maker’s site) · Install Node.js on your computer first (one time)

B · Others in Chat & email that work with ChatGPT

Picked from the most used in the same category, only ones that connect by address with no key

HyperFrames by HeyGen✓ ChatGPT
Inbox Zero✓ ChatGPT
emailmd✓ ChatGPT

Works with Claude Code, with some setup first

You need a MX Probe key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a Claude Code chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server MX Probe for Claude Code on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): claude mcp add --scope user mxprobe --env MXPROBE_API_KEY=your-value -- npx -y mxprobe mcp 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) For MXPROBE_API_KEY, leave "your-value" in place and tell me to paste the real value myself into the file or the app’s field. Never ask me to type a key in chat. 5) Do what we agreed, then check that the MX Probe tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Sign up and create a MX Probe key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the MX Probe site ↗
Done
Open Terminal
Mac: press Command+Space and type Terminal · Windows: open PowerShell
Done
4
Paste this command and press Enter
```
claude mcp add --scope user mxprobe --env MXPROBE_API_KEY=your-value -- npx -y mxprobe mcp
```
Replace “your-value” with your key before pressing Enter
Paste the key only into the app’s field, never into a chat or to anyone
Done
Type /mcp in Claude Code
You should see MX Probe listed as connected
Done
Try it
Use MX Probe and tell me what you can do for me, then show me one thing
✓ If Claude Code says it is using MX Probe or shows a MX Probe tool in the answer, you are connected

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with Cursor, with some setup first

You need a MX Probe key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a Cursor chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server MX Probe for Cursor on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "mcpServers": { "mxprobe": { "command": "npx", "args": [ "-y", "mxprobe", "mcp" ], "env": { "MXPROBE_API_KEY": "your-value" } } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) For MXPROBE_API_KEY, leave "your-value" in place and tell me to paste the real value myself into the file or the app’s field. Never ask me to type a key in chat. 5) Do what we agreed, then check that the MX Probe tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Sign up and create a MX Probe key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the MX Probe site ↗
Done
Click this button to open Cursor
Open in Cursor
Cursor asks you to confirm; click Install
Done
Fill in your key
In the MX Probe settings, MXPROBE_API_KEY is empty; add your key and save
Paste the key only into the app’s field, never into a chat or to anyone
Done
Open the AI chat in Cursor in Agent mode
Done
Try it
Use MX Probe and tell me what you can do for me, then show me one thing
✓ If Cursor says it is using MX Probe or shows a MX Probe tool in the answer, you are connected

Menu names checked against Cursor’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with VS Code, with some setup first

You need a MX Probe key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a VS Code chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server MX Probe for VS Code on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "servers": { "mxprobe": { "type": "stdio", "command": "npx", "args": [ "-y", "mxprobe", "mcp" ], "env": { "MXPROBE_API_KEY": "your-value" } } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) For MXPROBE_API_KEY, leave "your-value" in place and tell me to paste the real value myself into the file or the app’s field. Never ask me to type a key in chat. 5) Do what we agreed, then check that the MX Probe tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Sign up and create a MX Probe key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the MX Probe site ↗
Done
Click this button to open VS Code
Open in VS Code
VS Code asks you to confirm; click Install
Done
Fill in your key
In the MX Probe settings, MXPROBE_API_KEY is empty; add your key and save
Paste the key only into the app’s field, never into a chat or to anyone
Done
Open the AI chat in VS Code in Agent mode
Done
Try it
Use MX Probe and tell me what you can do for me, then show me one thing
✓ If VS Code says it is using MX Probe or shows a MX Probe tool in the answer, you are connected

Menu names checked against VS Code’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Other apps that use MCP, such as Windsurf, Zed or Gemini CLI, each add servers differently. See how in the app list.

See every app that uses MCP →

JSON settings are under “For developers” below

Stuck? Ask people who use MX Probe💬 Discussion →

For developers: Terminal commands and JSON settings

Installed on your computer

Claude Code

claude mcp add --scope user mxprobe --env MXPROBE_API_KEY=your-value -- npx -y mxprobe mcp

Claude Desktop (claude_desktop_config.json)

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

Cursor (~/.cursor/mcp.json)

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

VS Code (mcp.json)

{
  "servers": {
    "mxprobe": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mxprobe",
        "mcp"
      ],
      "env": {
        "MXPROBE_API_KEY": "your-value"
      }
    }
  }
}

Values you fill in

MXPROBE_API_KEY secret required env
Hosted-tier API key from POST /v1/signup or the signup tool. Without it the verify tools run the free local DNS tier.

Descriptions are as written by the maker.

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

At a glance

GitHub stars i: 2 (Stars for the whole repo)
This repo holds several MCP listings; its stars count once in rankings
Downloads per weeki: 579/wk
Verified domain: ✓ mxprobe.dev
Licence i: MIT
Connection: Runs on your computer
Transport: stdio
Latest versioni: 0.2.8
Categoryi: Chat & email
Published to registryi: Nov 4, 2026
Code last changedi: Nov 14, 2026
Maker: andrewchmr
Packages: npm: mxprobe
Repo: andrewchmr/mxprobe
Website: mxprobe.dev
Registry status: Active

Which apps can use it

Based on how this server connects and on each app’s own docs, checked Nov 10, 2026.

Run on your computer in

Claude Goose LM Studio Msty Studio Cherry Studio Cursor VS Code + GitHub Copilot Visual Studio Windsurf (Devin Desktop)Zed Kiro Cline Continue JetBrains AI Assistant Claude Code Codex CLI Gemini CLI OpenCode nodecode Warp LibreChat Raycast

All apps, with pros and cons →

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 15, 2026

✓ Pass
Maker matches the repo
The registry name was verified against the domain mxprobe.dev (the registry checks domain ownership)
✓ Pass
Still maintained
Code last changed yesterday
✓ Pass
Has a licence
Uses MIT
– 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

Published vulnerabilities (OSV.dev)

No entries on OSV.dev for mxprobe@0.2.8

Checks only this package version, not every dependency · checked Nov 15, 2026

What we check → · JSON

Makers: ask for a re-check or report wrong info

Discussion

Ask, share a tip or report that it does not work. Sorted by what people marked helpful.

No posts yet. Be the first to ask or share.

Posts here are written by users, not the PopNx team.

User reviews

No reviews yet

Compared with others in Chat & emaili

More stars than 0% of the other 2055 servers in this category
Published to the registry more recently than 72% of the other 2055 servers in this category
Basic checks equal to or better than 100% of the other 2055 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 MX Probe safe?

It passed 3 of 3 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: MXPROBE_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 yesterday, and the latest version (0.2.8) reached the registry 11 days 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: draw.io, Vexa, emailmd, Kite Discord Bot Builder, e2a — email for AI agents

Similar alternatives

Same category, other makers, commands already checked. Official ones first, then by stars.

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

draw.io

Create draw.io diagrams in chat from Mermaid or XML, shown live and interactive. 10,000+ shapes.

by jgraphWidely used★ 5.8KUpdated 5 days ago

Runs in the cloud✓ service owner · draw.ioTried by the PopNx team

How to connect

Vexa

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

by Vexa-aiWidely used★ 3KUpdated 2 months ago

Runs in the cloud✓ service owner · vexa.ai

How to connect

emailmd

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

by anypostWidely used↓ 5.4K/wk★ 1.4KUpdated yesterday

Computer or cloud✓ service owner · emailmd.dev

Install

Kite Discord Bot Builder

Build and fix Discord bots from a chat. Kite hosts them 24/7, with no code to deploy.

by merlinfuchsGrowing★ 334 Stars for the whole repoUpdated 18 days ago

Runs in the cloud✓ service owner · kite.onl

How to connect

e2a — email for AI agents

Authenticated email gateway for AI agents — per-agent inboxes, HITL approval, SPF/DKIM verified.

by tokencanopyGrowing★ 199 Stars for the whole repoUpdated 4 months ago

Runs in the cloud✓ service owner · e2a.dev

How to connect

draw.io — Runs in the cloud, nothing to install · No key needed
Vexa — Runs in the cloud, nothing to install · Needs a key
emailmd — Cloud or install on your computer · No key needed
Kite Discord Bot Builder — Runs in the cloud, nothing to install · No key needed
e2a — email for AI agents — Runs in the cloud, nothing to install · No key needed

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.

mxprobe

Email verification for AI agents. One call returns send, hold or kill with the reason. The DNS tier is free and runs on your machine; the hosted SMTP probe is 9 USD per 10,000 checks, 100 free at signup (once per IP address and company domain).

npx mxprobe check hello@example.com ops@example.org   # free, local, no key

npx mxprobe signup you@company.com # a key by API, 100 free checks, saved to ~/.config/mxprobe npx mxprobe check --hosted hello@example.com # DNS kills stay local; survivors go to the mailbox probe npx mxprobe balance npx mxprobe buy # a Stripe link: 9 USD per 10,000, credits never expire npx mxprobe mcp # the MCP server on stdio

--smtp probes the mailbox from your own machine instead. It needs outbound port 25, which most laptops and clouds block. The probe says EHLO with this machine's host name and MAIL FROM:<>, so it names no domain; --helo (best: the reverse DNS name of your IP) and --from change them.

MCP

claude mcp add mxprobe -- npx -y mxprobe mcp

One click: Cursor · VS Code · LM Studio. In Claude Code, as a plugin: /plugin marketplace add andrewchmr/mxprobe, then /plugin install mxprobe@mxprobe.

Any client: {"mcpServers":{"mxprobe":{"command":"npx","args":["-y","mxprobe","mcp"]}}}

Tools: verify_email, verify_batch, signup, balance, buy_credits. With a key configured, verify_* probe the mailbox on the hosted tier; without one they run the free DNS tier. Set MXPROBE_API_KEY to use a key from the environment.

Verdict

"email": "hello@example.com", "action": "send", "verdict": "OK", "reason": "mailbox accepted by aspmx.l.google.com", "checks": { "syntax": true, "mx": "aspmx.l.google.com", "provider": "google_workspace", "smtp": "accepted", "catch_all": false } }

send: the mail server accepted the mailbox.
hold: send only with a fallback in hand. A catch-all, a forwarder, a greylist, or a server that refused the probe rather than the mailbox.
kill: never send. No mail server, or the mailbox does not exist.

From Node

import { createClient, checkEmails } from "mxprobe";

const client = createClient({ apiKey: process.env.MXPROBE_API_KEY }); const { results, summary } = await checkEmails(["a@b.com"], { hosted: true, client });

Typed: Client, CheckOptions, CheckOutput and the response types come with the package; results is VerifyResult[] from mxprobe-core.

Docs: https://mxprobe.dev. Source: https://github.com/andrewchmr/mxprobe. MIT.

MX Probe

What it does

Install

Install Node.js (if you don’t have it)

Sign up and create a MX Probe key

Open the Claude desktop app’s settings file

Paste these settings and save the file

Quit Claude and open it again

Try it

What you can do instead

Install Node.js (if you don’t have it)

Sign up and create a MX Probe key

Open Terminal

Paste this command and press Enter

Type /mcp in Claude Code

Try it

Install Node.js (if you don’t have it)

Sign up and create a MX Probe key

Click this button to open Cursor

Fill in your key

Open the AI chat in Cursor in Agent mode

Try it

Install Node.js (if you don’t have it)

Sign up and create a MX Probe key

Click this button to open VS Code

Fill in your key

Open the AI chat in VS Code in Agent mode

Try it

Installed on your computer

Values you fill in

At a glance

Which apps can use it

Related guides

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

Published vulnerabilities (OSV.dev)

Discussion

User reviews

Compared with others in Chat & emaili

Common questions

Similar alternatives

draw.io

Vexa

emailmd

Kite Discord Bot Builder

e2a — email for AI agents

README from the maker

mxprobe

MCP

Verdict

From Node