DomainPulse
FREE DOMAIN TOOL

STARTTLS Test

Verify that an SMTP server advertises and successfully negotiates STARTTLS.

What DomainPulse checks

EHLO advertisement, STARTTLS response, TLS handshake, negotiated protocol and cipher.

Common problems

Missing advertisement, rejected upgrade and TLS handshake failures.

FAQ

Is advertised STARTTLS enough?

No. DomainPulse also performs the TLS handshake.

Is TLS 1.0 accepted?

The scanner requires modern TLS 1.2 or later.