tumgreyspf(8) on Linux
The text 77846cfbaaeb, as Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze), Debian 5.0 (Lenny) shipped it. The page shows this text now.
an external policy checker for the postfix mail server