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. You can verify this by –

# pear list | grep Netpear list|grep Net_Socket

Net_Socket       1.0.9   stable

In case this is not installed, you can install it-

pear install Net_Socket

If it is already present, check if the file Socket.php is present in /usr/share/pear/Net/ folder. Most probably this will be missing.

In case this is missing, download the package Net_Socket –

wget http://download.pear.php.net/package/Net_Socket-1.0.8.tgz

tar -xzvf Net_Socket-1.0.8.tgz

cd Net_Socket-1.0.8

cp Socket.php /usr/share/pear/Net/

You can now login to Horde Webmail Interface and no more see the error.