SMTP Server Checker
SMTP (Simple Mail Transfer Protocol) is the foundation of email delivery. Connection failures, missing STARTTLS support, or expired TLS certificates on your mail server can silently prevent email from being sent or received. Enter a domain to test its SMTP configuration.
What does this check?
- TCP connectivity to your mail server on port 25
- STARTTLS support for opportunistic TLS encryption
- TLS certificate validity and expiry date
- SMTP banner and server greeting response
- Whether the server accepts connections without timing out