messages.mailutils(1) on Linux
The text 562066012dd7, as Debian 9 (Stretch) shipped it.
count the number of messages in a mailbox
Flags it lists
-
--config-file -
--config-help -
--config-lint -
--config-verbose -
--debug-level -
--debug-line-info -
--help -
--no-config -
--no-site-config -
--no-user-config -
--quiet -
--set -
--show-config-options -
--silent -
--usage -
--version -
-? -
-V -
-q -
-s