Disposable Email Detector

Test any email address instantly against 1,000,000+ known disposable domains and real-time MX server fingerprinting. Stop burner signups, fake trials, and hard bounces before they pollute your CRM.

Why block disposable emails at signup?

• They never engage: Zero opens and clicks signal to Gmail and Yahoo that your domain sends unwanted mail.
• They hard-bounce within hours: Most temp-mail inboxes self-destruct in 10–60 minutes, triggering immediate hard bounces on your welcome sequence.
• They abuse free trials & promos: Burner domains are the #1 vector for coupon abuse and multi-accounting.
• They inflate ESP bills: You pay HubSpot, Mailchimp, or Klaviyo every month for dead contacts.

How our 4-layer detection engine works

1. 1,000,000+ Domain Blacklist: Instant lookup against Mailinator, 10minutemail, TempMail, YOPmail, Guerrilla Mail, TrashMail, Sharklasers, and 1M+ burner domains.
2. MX Server Fingerprinting: Even brand-new domains registered 5 minutes ago are caught when their MX records point to known disposable mail hosts.
3. Entropy & Pattern Heuristics: Detects automated local-part generation and high-risk free TLDs (.tk, .ml, .cf, .gq).
4. Real-Time SMTP Probe: Identifies catch-all honeypots and dead mail exchangers in milliseconds.

Categories of temporary & alias addresses

Block burner emails in your signup form (REST API)

curl -X POST https://kaijuverifier.com/api/v1/verify-single \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email": "temp@10minutemail.com"}'

# 200 OK (in ~85 ms)
{
  "email": "temp@10minutemail.com",
  "status": "invalid",
  "grade": "F",
  "score": 5,
  "checks": {
    "syntax": true,
    "dns": true,
    "is_disposable": true,
    "role_based": false,
    "catch_all": false
  },
  "reason": "disposable_domain"
}

See full examples in PHP, Python, Node.js and Go in our REST API Documentation →

Frequently Asked Questions: Disposable Email Detection