postfix mail server configuration in linux step by step

$ wget https://github.com/roundcube/roundcubemail/releases/download/1.4.8/roundcubemail-1.4.8.tar.gz
$ tar -xvf roundcubemail-1.4.8.tar.gz
$ sudo mv roundcubemail-1.4.8 /var/www/html/roundcubemail
$ sudo chown -R www-data:www-data /var/www/html/roundcubemail/
$ sudo chmod 755 -R /var/www/html/roundcubemail/