MailboxValidator MCP server
io.github.MailboxValidator/mcp-mailboxvalidator·v1.0.0·1 starsEmail validation MCP server using the MailboxValidator API. It can validate email addresses.
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 postsRead from the package source without running it. The installed server may list more.
check_disposable_emailwrite actionChecks if an email address is a disposable email using MailboxValidator.
check_free_emailwrite actionChecks if an email address is a free email using MailboxValidator.
validate_emailwrite actionChecks 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
- 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
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
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:
- Download the repository to your local.
- Run the following commands while inside the project folder to install dependencies and build the server.
npm install
npm run build- 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.
- Open claudedesktopconfig.json. If you don't have that file yet, follow this guide to create one.
- 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>"
}
}
}
}- Remember to replace the path for the index.js with your actual path to your MailboxValidator MCP server on your local machine.
- 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.
- 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
Same job from other publishers: the closest match first, then the best rated.
- MailProbeVerify email addresses in real time: deliverability, disposable and role addresses, typo fixes.not reviewedGrowingA
- Tmailor temporary emailReceive-only temporary email addresses for AI agents: create an inbox, wait for an email, read it.not reviewedGrowingB
PidgeonEmail inboxes for AI agents: addresses, threads, sending and replies.not reviewedGrowingA- Mailoo - Email MCP ServerEmail MCP server for AI agents: IMAP/SMTP, Gmail, Outlook, calendar, ManageSieve, AI triage, OAuth2.5.0(1)GrowingA
- emailmdRender markdown into email-safe HTML, lint drafts for deliverability problems, and preview emails.not reviewedEstablishedA