Email Validation
Validate email addresses before outreach to protect your sender reputation and improve deliverability.
How Email Validation Works
Email validation is a multi-step process that checks if an email address is real and deliverable:
Validation Steps
- Syntax Check: Verifies the email follows proper format (e.g., [email protected])
- DNS Lookup: Checks if the domain exists and has valid MX records
- SMTP Verification: Connects to the mail server to confirm the mailbox accepts email
- Disposable Check: Detects temporary/disposable email services
- Risk Assessment: Identifies catch-all domains and other risk factors
Validation Statuses
After validation, each email is assigned one of these statuses:
Valid ✅
The email address exists and can receive mail. Safe to send.
Recommendation: Proceed with outreach.
Risky ⚠️
The email may exist but has risk factors (catch-all domain, role-based, etc.). May bounce.
Examples: [email protected], [email protected], catch-all domains
Recommendation: Use with caution. Consider manual review or secondary verification.
Invalid ❌
The email address does not exist or cannot receive mail. Will bounce.
Recommendation: Remove from outreach list to protect sender reputation.
Unknown ❓
Validation could not be completed (server timeout, temporary error, etc.).
Recommendation: Retry validation or proceed with caution.
Supported Providers
Hunter.io
- Best for: Email finder + verification in one service
- Accuracy: 95%+
- Cost: $49/mo for 1,000 verifications
- Setup: Hunter.io Integration Guide
BounceBan
- Best for: High-volume validation
- Accuracy: 98%+
- Cost: Pay-as-you-go pricing
- Setup: BounceBan Integration Guide
Mailveri
- Best for: Budget-friendly validation
- Accuracy: 95%+
- Cost: Lower pricing tiers
- Setup: Mailveri Integration Guide
Batch Validation Workflows
Validate thousands of leads efficiently with batch processing:
- Select all leads in your pipeline (or filter first)
- Click Validate Emails
- Choose your provider
- Watch real-time progress (processed/total, success rate)
- Review results when complete
Best Practices
Protecting Sender Reputation
- Always validate emails before cold outreach
- Remove Invalid statuses immediately
- Be cautious with Risky statuses (consider secondary verification)
- Keep bounce rates below 5% for optimal deliverability
Cost Optimization
- Clean obvious invalids locally first (typos, syntax errors)
- Validate in batches to use provider bulk pricing
- Cache validation results to avoid re-validating same emails
- Use lower-cost providers for non-critical campaigns
When to Validate
Always validate:
- Purchased or scraped lead lists
- Lists older than 6 months
- Before high-volume campaigns
May skip validation:
- Inbound leads from forms (already verified)
- Internal company emails
- Recently validated lists (< 30 days)
Troubleshooting
High "Unknown" Rate
Cause: Greylisting or temporary server issues
Solution: Retry validation after a few hours
Validation Timeouts
Cause: Large batch or slow provider API
Solution: Split into smaller batches (5,000 leads max)
API Rate Limits
Cause: Exceeded provider rate limits
Solution: Wait for rate limit reset or upgrade provider plan
Next Steps
- Add AI enrichment after validation
- Learn about batch processing for large lists
- Set up Hunter.io integration