Berkeley mail

/usr/bin/mail, /usr/ucb/mail

is from an older, less mobile era of email use. Today's email user demands flexible access to their email, from a variety of sources, including the Unix shell, a client like Thunderbird, Evolution, Mac Mail, or Outlook on their desktop, via the web with a Gmail-like interface, or through mobile devices like tablets and smart phones.
-------
Please visit the source wiki page for the rest of this article.