The Horde webmail interface may throw an error as – Warning: Failed opening ‘Net/Socket.php’ for inclusion (include_path=’.:/usr/share/pear’) in /usr/share/pear/Net/SMTP.php on line 93 Fatal error: Cannot instantiate non-existent class: net_socket in /usr/share/pear/Net/SMTP.php on line 95 To fix this, you can do the following – First check if the Pear package Net_Socket is present on the server. […]