STARTTLS Test
Check whether SMTP connections can be encrypted.
What this test checks
STARTTLS advertisement, handshake, TLS version, cipher and certificate evidence.
Why this matters
SMTP reachability and encrypted transport are separate properties. A server can accept SMTP without completing a secure TLS upgrade.
How to fix common problems
Enable STARTTLS and serve a valid certificate for every public mail host.
FAQ
Is advertisement enough?
No. DomainPulse also checks whether the TLS handshake succeeds.