posttls-finger(1) on Linux
The text 3e2ed8f1f00f, as Debian 12 (Bookworm) shipped it.
Probe the TLS properties of an ESMTP or LMTP server.
Flags it lists
-
-C -
-S -
-X -
-c -
-f -
-o -
-r -
-s -
-v -
-w