With the minimum installation of any Linux operating system, you will not see most of commands in your system. In minimum operating system installation only required packages are installed for running operating system and skipped unnecessary packages. mail command is useful for sending emails from Linux command line which is used for almost Linux operating system.
There are many other alternatives of mail command for sending emails from Linux command line interface. Visit here for more options.
Install mail Command:
Lets use one of below command to install mail command as per your operating system. For RHEL based systems, this command installed from mailx rpm packages and on Debian based system this command found in mailutils package.
Install mail command on CentOS/Redhat:
# yum install mailx
Install mail command on Ubuntu/Debian:
$ sudo apt-get install mailutils
Sending Test Email
After installing mail command packages in your system, send a test email using below command.
# echo "Message Body" | mail -s "Message Subject" [email protected]