use composer to build roundcubemail
there's pear-php packages like community/php7-pear-net_smtp which looks not used anymore
Ref https://github.com/roundcube/roundcubemail/wiki/Installation#install-dependencies
there's pear-php packages like community/php7-pear-net_smtp which looks not used anymore
Ref https://github.com/roundcube/roundcubemail/wiki/Installation#install-dependencies