This manual page documents briefly the mailer command, which is part of the john package. This manual
page was written for the Debian GNU/Linux distribution because the original program does not have a
manual page. john, better known as John the Ripper, is a tool to find weak passwords of users in a
server.
The mailer tool is useful to inform users which have been found to be using weak passwords by mail.
You should edit the message mailer will send to the users, but remember to copy the script to a safe
place before editing it, as it's generally a bad idea to modify things living in /usr.