doveadm-purge(1) on Linux
The text 3fa7c478f9d8, as Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster) shipped it.
Remove messages with refcount=0 from mdbox files
Flags it lists
-
-A -
-D -
-F -
-S -
-o -
-u -
-v