Send email from command line with OpenSUSE, Postfix and relayhost

For sending email from command line to an email address via a relay host with Postfix in OpenSUSE, do the following:
Edit postfix main configuration file (/etc/postfix/main.cf) to


relayhost = [relayhost.com]


Then install a simple sending email utility (mail)


#zypper install mail


Then  try to send email from command line with:


#mail -s "Test email" recipient@mail.com
Test
.