There are quite a few ways to send email from the Unix command line and so many good reasons for doing so. You might want to provide feedback on automated processes so that you and fellow admins know ...
Unix was developed as a command line interface in the early 1970s with a very rich command vocabulary. DOS followed more than a decade later for the IBM PC, and DOS commands migrated to Windows.
A common task of sysadmins is to generate email messages and send them out to a group of people. Reminders about upcoming system downtime or tips to help users make better use of their Unix accounts ...