Checkmails — Email Verification

Installation

No local package target is declared for this server. Connect to the hosted remote MCP endpoint documented by Checkmails.

Claude Code:

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

Cursor / Claude Desktop / generic MCP clients:

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

Replace the documented placeholder key with a Checkmails API key generated from the Checkmails dashboard.

Configuration

Remote target: streamable-http at https://checkmails.eu/api/mcp. Authentication is via the required HTTP header Authorization: Bearer chk_<key>. Checkmails documents that MCP/REST API access requires a paid account/API key.

Capabilities

The MCP guide and API documentation describe three MCP tools:

• verify_email(email): verifies one email address by SMTP RCPT TO without sending a message; returns verdict, risk score, and diagnostic flags; costs 1 credit.
• verify_bulk(emails[], consent?): submits up to 1000 email addresses for asynchronous verification and returns a job_id; costs 1 credit per definitive valid/invalid address in the MCP guide, while OpenAPI notes REST bulk credits are deducted upfront for syntactically valid emails.
• get_job(job_id): retrieves status and results for a bulk verification job.

Related REST/OpenAPI endpoints are POST /api/v1/verify, POST /api/v1/bulk, and GET /api/v1/jobs/{id}.

Limitations

Checkmails documents paid-plan/API-key access, credit billing, and rate limits. OpenAPI lists POST /api/v1/verify as rate-limited at 60/min/api-key and POST /api/v1/bulk at 10/min/api-key. Bulk verification is capped at 1000 email addresses per call. Errors include missing/invalid API key, insufficient credits, and rate limiting. The docs state indeterminate results can occur for providers such as Apple/iCloud and sometimes Outlook, and should not be treated as invalid; indeterminate results are documented as not billed. Bulk jobs are asynchronous and must be polled with get_job//api/v1/jobs/{id}.