messages.mailutils(1) on Linux
The text 93653ed6e0f7, as Debian 11 (Bullseye) shipped it.
count the number of messages in a mailbox
Flags it lists
-
--config-file -
--config-help -
--config-lint -
--config-verbose -
--debug-level -
--help -
--no-config -
--no-site-config -
--no-user-config -
--set -
--show-config-options -
--usage -
--version -
-? -
-V