The definitive guide to email validation. Learn advanced techniques used by industry leaders to maintain 99.9% deliverability rates.
Learn everything about email validation, from basic syntax checking to advanced SMTP verification techniques.
Email validation is a sophisticated process that verifies email addresses before sending campaigns. It combines multiple verification techniques including syntax checking, domain validation, SMTP verification, and mailbox existence testing to ensure your emails reach real inboxes.
Industry Fact:
23% of email addresses entered online contain typos or are fake. Without validation, nearly 1 in 4 emails will bounce, damaging your sender reputation.
Invalid emails damage sender reputation. ISPs track bounce rates and blacklist senders exceeding 2% bounces.
Stop paying for invalid addresses. Most ESPs charge per email - validation saves thousands monthly.
Clean lists have higher open rates (25% vs 15%) and click rates (4% vs 1.5%) than unvalidated lists.
Bounce rates over 5% trigger spam filters. Validation keeps you in the inbox, not the spam folder.
Validates email structure against RFC 5322 standards. Checks for valid characters, proper @ placement, and domain format.
✅ Valid: john.doe+tag@company.com❌ Invalid: john..doe@@company..comVerifies domain exists and is configured for email. Checks DNS records, domain age, and registration status.
Validates Mail Exchange (MX) records to ensure the domain can receive emails. Checks priority levels and mail server availability.
MX Priority 10: mail.example.com
MX Priority 20: backup.example.com
Connects to the mail server via SMTP to verify mailbox existence without sending an email. Uses advanced techniques to bypass greylisting.
Advanced analysis including disposable email detection, role-based identification, typo correction, and deliverability scoring.
High Risk:
Disposable, role-based, honeypots
Low Risk:
Personal, corporate, verified
20% of business domains accept all addresses, making individual validation difficult.
Solution: Use risk scoring, domain reputation analysis, and engagement tracking to identify valid addresses.
15% of servers use greylisting, temporarily rejecting first validation attempts.
Solution: Implement retry logic with exponential backoff and distributed validation IPs.
Major providers limit validation attempts to prevent abuse.
Solution: Use IP rotation, respect rate limits, and implement smart caching strategies.
Modern servers implement strict security to prevent email harvesting.
Solution: Use ethical validation methods, maintain compliance, and respect privacy laws.
Validate emails instantly at form submission to prevent bad data entry.
Re-validate lists every 3 months - 30% of emails decay annually.
Combine validation with confirmation emails for maximum accuracy.
Track bounce rates, engagement, and validation metrics daily.
Remove hard bounces instantly to protect sender reputation.
Treat risky emails differently - lower frequency, different content.
Add real-time validation to forms with JavaScript SDK.
emailCheck.validate(email)Process multiple emails efficiently with parallel API calls.
GET /v1-get-email-details (parallel)Get instant validation results with comprehensive details.
GET /v1-get-email-detailsBased on average list of 100,000 emails with 23% invalid rate
99.9% accurate. Multi-layer verification with SMTP checks reduces false positives to near zero.
No! 25ms average response time. Users won't notice any delay during form submission.
Yes! Process 1M emails per batch via CSV upload or API. Results ready in minutes.
Yes! Fully GDPR/CCPA compliant. No personal data storage, privacy-safe processes.
Never! We use SMTP handshake to verify mailboxes without sending any emails.
We detect 5,000+ disposable domains updated hourly. Prevents fake signups and protects deliverability.
Join 50,000+ companies reducing bounce rates by 95%
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