email-finder（电子邮件查找器）

Email Finder

Discover email addresses associated with a domain using multiple methods.

How It Works

1. Website Scraping — Fetches homepage, /contact, /about, /team pages and extracts emails via regex
2. Search Dorking — Searches for published emails in directories and search engines
3. Pattern Guessing — If a name is provided, generates common patterns (first@, first.last@, flast@, etc.)
4. DNS Hints — Checks MX/SPF/DMARC records to identify the email provider
5. SMTP Verification — Verifies all found/guessed emails using RCPT TO

Dependencies

pip3 install dnspython

Usage

Basic domain search

python3 scripts/find_emails.py example.com

With name for pattern guessing

python3 scripts/find_emails.py example.com --name "John Smith"

Skip SMTP verification

python3 scripts/find_emails.py example.com --no-verify

Options

• --name "First Last" — Enable pattern guessing for a specific person
• --no-verify — Skip SMTP verification step
• --timeout SECONDS — Connection timeout (default: 10)

Output

JSON to stdout:

{
  "domain": "example.com",
  "provider": "Google Workspace",
  "mx": ["aspmx.l.google.com"],
  "spf": "v=spf1 include:_spf.google.com ~all",
  "dmarc": "v=DMARC1; p=reject; rua=mailto:dmarc@example.com",
  "emails_found": 2,
  "emails": [
    {
      "email": "info@example.com",
      "source": "scraped",
      "deliverable": "yes",
      "smtp_detail": "2.1.5 OK"
    },
    {
      "email": "john.smith@example.com",
      "source": "guessed",
      "deliverable": "catch-all",
      "smtp_detail": "2.1.5 OK"
    }
  ]
}

Source values

Deliverable values

Rate Limiting

The script includes built-in rate limiting at every stage to protect your IP:

# Defaults: 0.5s between page fetches, 2s between SMTP checks, max 15 SMTP checks
python3 scripts/find_emails.py example.com --name "John Smith"

# Conservative settings for sensitive environments
python3 scripts/find_emails.py example.com --scrape-delay 1.0 --smtp-delay 4 --max-smtp-checks 8

# Just scrape, no SMTP (zero risk)
python3 scripts/find_emails.py example.com --no-verify

Options

• --scrape-delay SECONDS — Pause between website page fetches (default: 0.5)
• --smtp-delay SECONDS — Pause between SMTP verification checks (default: 2.0)
• --max-smtp-checks N — Max SMTP verifications per run (default: 15). Remaining emails get not_checked status.

Why rate limiting matters

This tool hits both web servers and mail servers. Without rate limiting:

• Web scraping — Aggressive crawling gets your IP blocked by WAFs (Cloudflare, etc.) and makes you look like a bot. Respectful delays avoid this.
• SMTP verification — Mail servers flag IPs making rapid RCPT TO requests. Your IP can get blacklisted, affecting your ability to send real email.
• Residential IPs are fragile — Unlike datacenter IPs, your home/office IP is shared across all your internet activity. Getting it blacklisted affects everything.

Guidelines for agents

Key principle: The script is designed for targeted lookups, not mass scraping. If you need to process hundreds of domains, use a dedicated service with proper IP reputation management.

Limitations

• Website scraping depends on emails being visible in page source (won't find obfuscated/JS-rendered emails)
• Search engines may block automated queries
• SMTP verification requires outbound port 25 access
• Catch-all domains accept all addresses — can't confirm real inboxes
• Be respectful: the script adds delays between requests but don't run it in tight loops