Mail port check
Checks 25, 465, 587, 993, 995 only (≈3s timeout each). Use on mail hosts you administer. This is not a general port scanner.
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Honest note & scope: We open TCP connections from our server to the resolved public IPs on ports 25, 465, 587, 993, 995 only. Private ranges are blocked. Do not use this against systems you do not administer. This is intentionally not a general port scanner.
Mail-port reachability for administrators
When setting up Postfix, Exchange, or a hosted mail relay, confirming submission (587), SMTPS (465), and secure IMAP/POP can save time. This check is limited to those mail-related ports plus SMTP 25.
Frequently asked questions
Why only five ports?
To avoid building a general scanner. These are the common mail service ports.
Port 25 closed?
Many networks block outbound 25; a closed result may be filtering, not your server.
Is this unauthorized scanning?
Only use on hosts you own or are authorized to test.