See exactly what we check
Three layers of validation. Complete transparency. No black boxes. See how each layer protects your specific use case.
Three layers. Complete transparency.
Each layer catches different problems. See how each one protects your specific use case.
Syntax Validation
RFC-compliant format checking. Catches typos, missing @ symbols, and malformed addresses instantly.
Valid format
Missing @ symbol
userexample.com
- • Valid local part (before @)
- • Valid domain format
- • No consecutive dots
- • Proper character encoding
MX Record Check
Verifies the domain has valid mail servers configured. Catches fake domains and parked domains.
Valid mail server
gmail.com has MX records
Disposable domain
10minutemail.com is a temp mail provider
- • Domain has MX records
- • Mail server responds
- • Domain isn't parked
- • Not a disposable domain
SMTP Verification
Connects to the mail server to verify the mailbox actually exists. The most accurate validation possible.
Mailbox exists
Server confirms [email protected] exists
Catch-all domain
Server accepts all addresses (flagged)
- • Mailbox accepts mail
- • Not a full mailbox
- • Not greylisted
- • Flags catch-all domains
Additional detection features
Beyond the three validation layers, we catch specific problem types.
Disposable emails
15,000+ temporary email domains blocked. Updated daily.
Role-based emails
Identify generic addresses with low engagement (info@, admin@, support@).
Catch-all flagging
Detects domains that accept all email addresses. Flagged for your review.
Custom blacklists
Build your own filters for emails, domains, and IPs.
Bulk processing
Upload CSV files with thousands of emails. Parallel processing.
REST API
Validate emails in real-time from any application. JSON responses.
What we can't catch
Honesty builds trust. Here's what no validation tool can guarantee.
Catch-all domains
Some domains accept all email addresses. We flag these so you can decide. They're hard for every tool.
Greylisting
Some servers temporarily reject emails to stop spam. We retry, but can't guarantee immediate results.
Inactive mailboxes
A valid mailbox might belong to someone who never checks it. We verify existence, not engagement.
Rate limiting
Some mail servers limit validation requests. We spread out checks, but some domains remain hard to verify.
Ready to validate?
Choose your path based on what you're trying to accomplish.
Sales Teams
Protect your sender reputation and improve cold outreach deliverability.
Protect your domainOr start with 100 free validations
Start validating free