Email Mailbox Checker - Verify Email Validity & Deliverability
Check if an email address is valid, verify domain existence, MX records, and SMTP connectivity. Get confidence levels to determine email deliverability.
Verify email address validity, check domain existence, MX records, and SMTP connectivity. Get confidence levels to determine if an email is safe to send to.
How It Works
This tool performs multiple checks to validate an email address and determine its deliverability.
- Validates email syntax using PHP filter_var
- Checks if the domain exists via DNS lookup
- Verifies MX (Mail Exchange) records are present
- Attempts SMTP handshake to verify mailbox (when possible)
Important Notes
- SMTP verification may not work for all providers (Gmail, Outlook, etc. often block unknown IPs)
- Some domains use catch-all addresses that accept all emails but bounce later
- Results are confidence levels, not absolute guarantees of deliverability
- Modern email providers may accept RCPT TO but bounce messages later
