MCP.Market

MailboxValidator MCP server

by MailboxValidator·io.github.MailboxValidator/mcp-mailboxvalidator·v1.0.0·1 stars

Email validation MCP server using the MailboxValidator API. It can validate email addresses.

B74/100grade B
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Safety scan
B74/100

full report

Adoption
New

1 stars29 downloads/wk

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If you have run it, two minutes of your experience saves the next person an afternoon.

MailboxValidator tools (3, 3 write)

write = sends, deletes, buys or posts

Read from the package source without running it. The installed server may list more.

  • check_disposable_emailwrite action

    Checks if an email address is a disposable email using MailboxValidator.

  • check_free_emailwrite action

    Checks if an email address is a free email using MailboxValidator.

  • validate_emailwrite action

    Checks if an email address is valid and reachable using MailboxValidator.

Public scan report

scanner v0.1.9 · 2026-09-27 · same rubric, same numbers if you re-run it

no findings
  • Code scan2 source files scanned25/25
  • –Live reliabilityno gateway calls yet and no remote to proben/a
  • –Tool poisoningtools not inspected (local package is not executed); not countedn/a
  • Auth qualitystatic API keys via environment variables6/15
  • Maintenancelast push 116 days ago8/15
  • Maintainer identityregistry namespace matches repository owner; GitHub account older than a year9/10
Overall 74/100. Components that don't apply are left out of the denominator. Any critical finding is an F.RubricAppeal a findingJSON

How MailboxValidator compares

Against every graded Email MCP server, from our own scans and uptime checks. Updated after each scan run.

Safety score
74/100
higher than 44% of 916 Email servers
Tools
3
the typical Email server has 7
Tools that change things
100%
typical: 25%. Fewer write tools means less an agent can break
GitHub stars
1
more than 65% of 493 Email servers
Downloads a week
29
more than 13% of 235 Email servers with a package

What its tools let an agent do: 3 change

Install MailboxValidator in Claude Code, Cursor or VS Code

Runs npx -y mcp-mailboxvalidator on your machine. Read the scan report first; the gateway never runs local packages.

claude mcp add mcp-mailboxvalidator -- npx -y mcp-mailboxvalidator
Add to Cursor

What the publisher says

From the MailboxValidator repository's README, as published. We do not edit it. Read it on GitHub

MailboxValidator MCP server

This is a simple Model Context Protocol (MCP) server implementation for MailboxValidator API. It will return validation result for an email address.

Features

  • Comprehensive Email Validation: Checking an email address to see if an email is reachable by checking the syntax, DNS, MX server, high risk, suppressed list, and more.
  • Disposable Email: Checking an email address to see if it's from a temporary/disposable email provider.
  • Free Email: Checking an email address to see if it's from a free email provider.

Requirement

This MCP server requires an API key. You can also sign up for a free API key and enjoy up to 300 queries per month.

The setup also uses Node.js and npm, which can be downloaded at Node.js website.

Setup

Follow the steps to use this MCP server with Claude Desktop:

  1. Download the repository to your local.
  2. Run the following commands while inside the project folder to install dependencies and build the server.
npm install
npm run build
  1. Make sure you have installed Claude Desktop. If you haven't, kindly download from here for Windows and macOS users, or follow this guide for Linux users.
  2. Open claudedesktopconfig.json. If you don't have that file yet, follow this guide to create one.
  3. Add the following to your claudedesktopconfig.json:
{
  "mcpServers": {
    "mailboxvalidator": {
      "command": "node",
      "args": [
        "C:\\path\\to\\mcp-mailboxvalidator\\build\\index.js"
      ],
      "env": {
        "MAILBOXVALIDATOR_API_KEY": "<YOUR_API_KEY>"
      }
    }
  }
}
  1. Remember to replace the path for the index.js with your actual path to your MailboxValidator MCP server on your local machine.
  2. To get your API key, just login to your dashboard and get it from there. Replace the in the above with your actual API key.
  3. Restart the Claude Desktop after saving the changes, and you should see it appear in the Search and tools menu.

Usage

Just enter your query about the email address in a chat in Claude Desktop. Some of example queries are:

  • Is (email) a valid email address?
  • Is (email) a fake email?
  • Is (email) a free email?

In Claude Desktop, the model will automatically generate the output based on the result returned by MailboxValidator MCP server.

Environment Variable

MAILBOXVALIDATORAPIKEY

The free MailboxValidator API key allows you to query up to 300 emails per month. If you require more, you can sign up for a paid API plan.

Tool

validate_email

Description Validates the email address given. It helps users to determine if an email address is potentially reachable by checking the syntax, DNS, MX server, disposable list and more.

Arguments email (str): The email address to validate.

Returns A JSON string containing the validation data. The result includes the following fields:

Shortened. The full README is on GitHub.

Nothing above is checked by us. What we check is on the safety report.

MailboxValidator: common questions

Is MailboxValidator MCP server safe?
Mostly: it is graded B (74/100). Read the MailboxValidator safety report
How do I install MailboxValidator?
It runs on your machine. Copy the Claude Code, Cursor, VS Code or Claude Desktop config from the install section.
Does MailboxValidator need an API key?
Yes. The registry entry asks for MAILBOXVALIDATOR_API_KEY.
Is MailboxValidator maintained?
The last commit was 154 days ago (2026-06-03). The latest release is v1.0.0.
What can I use instead of MailboxValidator?
Servers from other publishers that do the same job: MailProbe MCP server, Tmailor temporary email MCP server and Pidgeon MCP server.
How does MailboxValidator compare with other Email MCP servers?
safety score 74/100 (higher than 44% of 916 Email servers); tools 3 (the typical Email server has 7); tools that change things 100% (typical: 25%. Fewer write tools means less an agent can break). Full comparison.

Alternatives to MailboxValidator

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