EMAIL & AUTHENTICATION ·
smtp:SMTP Diagnostics
Connect to a mail server: banner, EHLO, STARTTLS, reverse DNS, open relay and response times.
About the SMTP Diagnostics tool
Connect to a mail server: banner, EHLO, STARTTLS, reverse DNS, open relay and response times.
Tip: from any lookup box on the site you can type smtp:example.com to run this tool directly.
Results are generated live by querying the authoritative name servers of the domain, so changes you just published show up immediately. Each finding is graded as an error, warning or pass and explained so that you know what to fix and why it matters.