MailTester Email Verification

Name: MailTester Email Verification
Author: mailtester-com

by mailtester-comversion 1.0.1i★ –iRuns in the cloud

Registry namecom.mailtester/email-verification

Install

Overview

Description from the maker (original English)

Verify emails (valid/invalid/risky/unknown): MX, SMTP, catch-all, disposable. Free agent key.

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 in the cloud
Transport: Streamable HTTP
Category: Chat & email
You need to fill in: 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: 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

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.

Run this in your terminal

claude mcp add --transport http email-verification https://app.mailtester.com/mcp --header 'Authorization: your-value'

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": {
    "email-verification": {
      "url": "https://app.mailtester.com/mcp",
      "headers": {
        "Authorization": "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": {
    "email-verification": {
      "type": "http",
      "url": "https://app.mailtester.com/mcp",
      "headers": {
        "Authorization": "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

Authorization secret HTTP header
Bearer . Get a free key (25 verifications/day) with the get_api_key tool or POST https://app.mailtester.com/agent-gateway/register

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 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified against the domain mailtester.com (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 1778 servers in this category
Published to the registry more recently than 47% of the other 1778 servers in this category
Basic checks equal to or better than 100% of the other 1778 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 MailTester Email Verification 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: Authorization

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.0.1) reached the registry 29 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.

MailTester MCP server — email verification for AI agents

Remote Model Context Protocol server that tells an AI agent whether an email address can receive mail before anything is sent to it.

Endpoint: https://app.mailtester.com/mcp (Streamable HTTP, JSON responses)
Official MCP Registry: com.mailtester/email-verification
Website: https://mailtester.com
Agent docs: https://app.mailtester.com/agent-gateway · OpenAPI · llms.txt · agent card

The server is hosted; there is nothing to install. This repository documents how to connect.

Get a key (no account needed)

Connect without a key and call the get_api_key tool, or:

curl -X POST https://app.mailtester.com/agent-gateway/register \

-H 'Content-Type: application/json' \ -d '{"name":"my-agent","purpose":"verify signup emails"}'

The key is shown once. Each key gets 25 free verifications per day (unused credits do not roll over) and expires after 30 days; register again when it does. Send it as Authorization: Bearer .

Connect

Claude Code

claude mcp add --transport http mailtester https://app.mailtester.com/mcp --header "Authorization: Bearer YOUR_KEY"

Claude Desktop / Cursor / VS Code (`mcp.json`-style config)

"mcpServers": { "mailtester": { "type": "http", "url": "https://app.mailtester.com/mcp", "headers": { "Authorization": "Bearer YOUR_KEY" } } } }

Tools

Tool	What it does
`get_api_key`	Get a free key (works without a key)
`verify_email`	Verify one address → `valid`, `invalid`, `risky` or `unknown` (1 credit)
`verify_batch`	Verify up to 25 addresses per call, with per-address verdicts
`get_batch_status`, `list_lists`, `get_list`	Follow saved verification lists
`explain_result`	Explain a verdict in plain English, with a send recommendation
`estimate_cost`, `get_credit_balance`	Check credits before running

Verdicts

valid: the mailbox exists and accepts mail
invalid: the address or domain cannot receive mail
risky: accept-all (catch-all) domain, role or disposable address, or a Microsoft 365 address the mail server couldn't confirm
unknown: the receiving server gave no definitive answer

Limits

10 requests per minute per key, one request in flight per key, and a shared daily capacity for free agent keys (HTTP 429 until 00:00 UTC when it is used up). Inbox placement, blacklist monitoring and email finder need a full account at https://mailtester.com.

REST API

The same key works on the REST API: POST https://app.mailtester.com/api/v1/verify, POST https://app.mailtester.com/api/v1/verify/batch, GET https://app.mailtester.com/api/v1/credits. See the OpenAPI description.

MailTester Email Verification

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

MailTester MCP server — email verification for AI agents

Get a key (no account needed)

Connect

Tools

Verdicts

Limits

REST API