icat(1) on Linux
The text f3bdc6f32570, as Debian 3.0 (Woody), Debian 2.2 (Potato) shipped it.
"cat" a mailbox from an IMAP source
Flags it lists
-
-a -
-db -
-do -
-ds -
-fa -
-fd -
-ff -
-fn -
-fo -
-mb -
-mc -
-mf -
-ms -
-mt -
-mx