SMTP Test
Test your domain's mail server connectivity. Resolves MX records, checks if mail server ports are open (25, 465, 587), verifies STARTTLS support, and checks MTA-STS and TLS-RPT configuration.
What this tool checks
MX Record Resolution
Finds your mail servers by looking up MX records, sorts by priority, and resolves the primary server's IP address.
Port Connectivity
Probes ports 25 (SMTP), 465 (SMTPS), and 587 (Submission) to check which mail ports are accepting connections.
STARTTLS Support
Checks if your mail server supports TLS encryption for inbound email. Without STARTTLS, email is transmitted in plain text.
MTA-STS Policy
Checks for an MTA-STS DNS record and policy file that enforces TLS for inbound email delivery.
TLS-RPT Configuration
Checks for TLS Reporting records that let senders report TLS delivery failures to your domain.
AUTH Support
Detects if port 587 (submission) is open — indicating the server accepts authenticated email submission.