Email Finder Overview
Discover email addresses associated with a domain using a hybrid approach: free methods first (web scraping, pattern guessing, WHOIS lookup), then APIs (Hunter.io, Apollo.io, etc.) when keys are available.
When to Use Scan a domain to find associated emails Find contact emails for a company Replace email hunter functionality Find email patterns for a domain Verify email addresses Enrich contact data with discovered emails Project Context Discovery
Before finding emails:
Check for existing email discovery tools Review available API keys (Hunter.io, Apollo.io) Check compliance/privacy requirements Look for project-specific [project]-email-finder skill Methodology Free Methods (Primary) Web Scraping - Scan /contact, /about, /team pages for emails WHOIS Lookup - Query domain registration data Pattern Guessing - Generate patterns from names found on site: firstname.lastname@domain.com firstnamelastname@domain.com firstname@domain.com f.lastname@domain.com API Methods (If Keys Available) API Env Variable Purpose Hunter.io HUNTER_API_KEY Domain search + verification Apollo.io APOLLO_API_KEY Contact discovery Snov.io SNOV_CLIENT_ID/SECRET Email finder Clearbit CLEARBIT_API_KEY Company enrichment Email Result Interface interface EmailResult { email: string; source: 'web-scraping' | 'whois' | 'pattern-guessing' | 'hunter' | 'apollo'; confidence?: number; firstName?: string; lastName?: string; position?: string; verified?: boolean; }
Best Practices Rate limiting: Delay between requests (1s recommended) Respect robots.txt: Check before scraping Deduplicate: Normalize emails (lowercase, trim) Verify: Use MX record checks or API verification Filter: Remove noreply@, donotreply@ addresses Legal & Ethical Comply with GDPR/CCPA Respect terms of service Honor opt-out requests Don't spam discovered emails Integration
Works well with:
leads-researcher - Discover contact emails after researching companies copywriter - Use found emails for outreach campaigns
For complete implementation code, API examples, verification patterns, and rate limiting utilities, see: references/full-guide.md