messages.mailutils(1) on Linux
The text 3b23784d5f8f, as Debian 5.0 (Lenny) shipped it.
count the number of messages in a mailbox
Flags it lists
-
--help -
--license -
--lock-expire-timeout -
--lock-flags -
--lock-retry-count -
--lock-retry-timeout -
--mail-spool -
--mailbox-type -
--quiet -
--silent -
--tls -
--usage -
--version -
-? -
-V -
-m -
-q -
-s