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SMTP Tester

Test an SMTP endpoint's public connection path, TLS negotiation, server greeting and EHLO evidence without credentials or sending an email.

SMTP CONNECTIVITY

Test the public SMTP connection path.

InboxAI checks DNS resolution, connectivity, TLS negotiation, the SMTP greeting and EHLO evidence. The diagnostic is credential-free and does not send an email.

Enter only the SMTP hostname. Do not enter a username, password, OAuth token or API key.
Port
Security
Protected diagnosticCloudflare verifies this public request before InboxAI performs the server-side check.
Your browser sends the host, port, security mode and Turnstile proof only to the InboxAI Website boundary.
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