Prospector MCP

B2B email finder and verification — no paid API subscriptions required.

Prospector is a Model Context Protocol (MCP) server that finds and verifies business email addresses. Unlike Hunter.io, Apollo.io, or Lusha, Prospector does its own DNS/SMTP verification and web scraping. Zero external API costs.

Why Prospector?

Quick Start

With Claude Code

claude mcp add prospector -- npx prospector-mcp

With Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "prospector": {
      "command": "npx",
      "args": ["prospector-mcp"]
    }
  }
}

With Cursor / Windsurf

Add to your MCP settings:

{
  "prospector": {
    "command": "npx",
    "args": ["prospector-mcp"]
  }
}

Tools

verify_email

Verify if an email address is valid and deliverable. Performs DNS MX lookup, SMTP handshake (without sending email), catch-all detection, and disposable domain filtering. Returns a confidence score (0-100).

Input:  { "email": "jane@acmecorp.com" }
Output: { "email": "jane@acmecorp.com", "status": "valid", "score": 95, "mx_host": "aspmx.l.google.com", ... }

verify_emails_batch

Verify up to 25 emails in a single request. Efficient for cleaning outreach lists.

Input:  { "emails": ["jane@acme.com", "fake@nowhere.xyz"] }
Output: { "summary": { "total": 2, "valid": 1, "invalid": 1 }, "results": [...] }

find_emails

Find email addresses for a business. Scrapes their website for contact info, generates pattern-based candidates from a contact name, and SMTP-verifies everything it finds. This is your Hunter.io replacement.

Input:  { "domain": "acmecorp.com", "contact_name": "Jane Smith" }
Output: { "best_email": "jane.smith@acmecorp.com", "confidence": 95, "results": [...] }

check_domain

Quick check if a domain can receive email. Returns MX records and catch-all status. Does not count against your verification quota.

Input:  { "domain": "acmecorp.com" }
Output: { "can_receive_email": true, "mx_host": "aspmx.l.google.com", "catch_all": false }

usage_stats

Check your current daily usage quota and remaining verifications.

How It Works

1. DNS MX Lookup — Checks if the domain has mail exchange records
2. SMTP Handshake — Connects to the mail server and sends RCPT TO: to check if the mailbox exists (no email is sent)
3. Catch-All Detection — Tests a random address to detect domains that accept all emails
4. Web Scraping — Fetches the business website and contact pages, extracts email addresses and mailto: links
5. Pattern Generation — Generates common email patterns (first.last@, flast@, etc.) from a contact name
6. Confidence Scoring — Combines all signals into a 0-100 score

Pricing

Prospector uses a simple daily quota system:

Set your tier via environment variable:

PROSPECTOR_TIER=pro npx prospector-mcp

HTTP Server (Remote Deployment)

For remote deployment, Prospector includes an HTTP/SSE transport:

node src/http-server.js
# or
PROSPECTOR_PORT=8080 node src/http-server.js

Endpoints:

• POST /mcp — MCP Streamable HTTP endpoint
• GET /health — Health check with usage stats

Requirements

• Node.js 18+
• Network access to port 25 (SMTP) for email verification

Note: Some hosting providers and corporate networks block outbound port 25. If SMTP verification returns "unknown" for all emails, check your network's firewall rules.

License

MIT