SMTP Tester

A fast, modern SMTP probe & test tool for Windows.

What is SMTP Tester?

SMTP Tester is a Windows WPF tool for probing and validating SMTP connectivity, TLS modes, authentication, and message sending. It is intended for troubleshooting and configuration testing.

STARTTLS SSL/TLS Auth testing Transcript logging Profiles

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Screenshot

A quick look at the SMTP Tester UI.