Server data from the Official MCP Registry
Verify emails (valid/invalid/risky/unknown): MX, SMTP, catch-all, disposable. Free agent key.
About
Verify emails (valid/invalid/risky/unknown): MX, SMTP, catch-all, disposable. Free agent key.
Remote endpoints: streamable-http: https://app.mailtester.com/mcp
Security Report
Valid MCP server (1 strong, 1 medium validity signals). No known CVEs in dependencies. Imported from the Official MCP Registry. 1 finding(s) downgraded by scanner intelligence.
Endpoint verified · Open access · 1 issue found
Security scores are indicators to help you make informed decisions, not guarantees. Always review permissions before connecting any MCP server.
Permissions Found in Source Code
Found by scanning the linked source code. This listing connects to a hosted endpoint, so none of this runs on your machine: it describes what the server software does where it is hosted.
How to Connect
Remote Plugin
No local installation needed. Your AI client connects to the remote endpoint directly.
Add this to your MCP configuration to connect:
{
"mcpServers": {
"com-mailtester-email-verification": {
"url": "https://app.mailtester.com/mcp"
}
}
}Documentation
View on GitHubFrom the project's GitHub README.
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 <api_key>.
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 mailinvalid: the address or domain cannot receive mailrisky: accept-all (catch-all) domain, role or disposable address, or a Microsoft 365 address the mail server couldn't confirmunknown: 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.
Reviews
No reviews yet
Be the first to review this server!
More Developer Tools MCP Servers
Fetch
Freeby Modelcontextprotocol · Developer Tools
Web content fetching and conversion for efficient LLM usage
Git
Freeby Modelcontextprotocol · Developer Tools
Read, search, and manipulate Git repositories programmatically
Toleno
Freeby Toleno · Developer Tools
Toleno Network MCP Server — Manage your Toleno mining account with Claude AI using natural language.
MCP Marketplace
Freeby mcp-marketplace · Developer Tools
Search and install MCP servers from inside your AI client.
mcp-creator-python
Freeby mcp-marketplace · Developer Tools
Create, build, and publish Python MCP servers to PyPI — conversationally.
FinAgent
Freeby mcp-marketplace · Finance
Free stock data and market news for any MCP-compatible AI assistant.