Connect checkmails to your AI

Verify email deliverability from Claude, Cursor, or any MCP client. checkmails exposes a remote MCP (Model Context Protocol) server — one URL, your API key.

Server URL

Claude Code

Add the server with one command (replace chk_your_key with your API key):

claude mcp add --transport http checkmails https://checkmails.eu/api/mcp --header "Authorization: Bearer chk_your_key"

Cursor / Claude Desktop / generic

Add this entry to your MCP client configuration (replace chk_your_key with your API key):

{
  "mcpServers": {
    "checkmails": {
      "type": "http",
      "url": "https://checkmails.eu/api/mcp",
      "headers": { "Authorization": "Bearer chk_your_key" }
    }
  }
}

Tools

The server speaks JSON-RPC 2.0 (protocol revision 2025-06-18) and exposes three tools:

• verify_email(email) — verify a single address by SMTP (RCPT TO) without sending any message. Costs 1 credit. Returns a verdict (valid / invalid / indeterminate), a risk score (0–100) and diagnostic flags.
• verify_bulk(emails[], consent?) — verify a batch of up to 1000 addresses asynchronously. Returns a job_id. Costs 1 credit per address with a definitive verdict (valid or invalid). Optional consent flag to acknowledge recipient consent.
• get_job(job_id) — get the status and results of a bulk job.

Indeterminate results (catch-all, uncertain iCloud) are never billed.