posttls-finger(1) on Linux
The text f3d62551c22e, as Debian 11 (Bullseye), Debian 10 (Buster) 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