Test a TLSA Record

We will look up the TLSA record(s) published for this host/port in DNS, connect to the server to fetch the certificate it actually presents, and tell you whether they match.

The hostname of the server to test, e.g. smtp.example.com or mail.example.com.

Common ports: 25 / 587 SMTP  ·  465 SMTPS  ·  443 HTTPS  ·  993 IMAPS

Connection mode

Choose Direct TLS for services where TLS starts immediately (HTTPS on 443, IMAPS on 993, SMTPS on 465). Choose STARTTLS for SMTP on port 25 and 587.

We only connect to the host and port you specify, for the sole purpose of fetching its TLS certificate and the TLSA record published for it. Nothing you enter here is stored or logged.

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