Emaillistchecker.io Email Verification
Verify emails (valid/invalid/risky/unknown): MX, SMTP, catch-all, disposable. Free agent key.
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
claude mcp add --transport http emaillistchecker-io-email-verification 'https://platform.emaillistchecker.io/mcp' --header 'Authorization: <Bearer <api_key>. Get a free key (25 verifications/day) with the get_api_key tool or POST https://platform.emaillistchecker.io/agent-gateway/register>'
{
"mcpServers": {
"emaillistchecker-io-email-verification": {
"type": "http",
"url": "https://platform.emaillistchecker.io/mcp",
"headers": {
"Authorization": "<Bearer <api_key>. Get a free key (25 verifications/day) with the get_api_key tool or POST https://platform.emaillistchecker.io/agent-gateway/register>"
}
}
}
}
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
Contents
Emaillistchecker.io 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://platform.emaillistchecker.io/mcp(Streamable HTTP, JSON responses) - Official MCP Registry:
io.emaillistchecker/email-verification - Website: https://www.emaillistchecker.io
- Agent docs: https://platform.emaillistchecker.io/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://platform.emaillistchecker.io/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 emaillistchecker https://platform.emaillistchecker.io/mcp --header "Authorization: Bearer YOUR_KEY"
Claude Desktop / Cursor / VS Code (mcp.json-style config)
{
"mcpServers": {
"emaillistchecker": {
"type": "http",
"url": "https://platform.emaillistchecker.io/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://www.emaillistchecker.io.
REST API
The same key works on the REST API: POST https://platform.emaillistchecker.io/api/v1/verify, POST https://platform.emaillistchecker.io/api/v1/verify/batch, GET https://platform.emaillistchecker.io/api/v1/credits. See the OpenAPI description.
Frequently asked questions
What is Emaillistchecker.io Email Verification?
Verify emails (valid/invalid/risky/unknown): MX, SMTP, catch-all, disposable. Free agent key.
How do I install Emaillistchecker.io Email Verification?
It runs as a remote server. In Claude Code: claude mcp add --transport http emaillistchecker-io-email-verification 'https://platform.emaillistchecker.io/mcp' --header 'Authorization: <Bearer <api_key>. Get a free key (25 verifications/day) with the get_api_key tool or POST https://platform.emaillistchecker.io/agent-gateway/register>'. For other clients, paste the JSON configuration from this page into their MCP settings.
Does Emaillistchecker.io Email Verification need an API key?
Yes. It expects Authorization, which you set in its configuration.
Is Emaillistchecker.io Email Verification open source?
Its code is public on GitHub, but the repository does not declare a standard license.
Who maintains Emaillistchecker.io Email Verification?
It is published by Emaillistchecker-io. AI.tn lists it but does not maintain or endorse it.
From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.