Sometimes you see the following error at the middle of your Webmail Horde session :
Your Internet Address has changed since the beginning of your Mail session.
To protect your security, you must login again.
This error mostly occurs when the ISP is using proxy servers to filter the browsers content. The proxy server randomly change its IP address and thus cause you to fail the web mail security measures.
The solution is to turn off the ‘checkip’ parameter in the Horde’s configuration file. The configuration file is located as follows:
cPanel server : /usr/local/cpanel/base/horde/config/conf.php
Edit the respective configuration file depending on the control panel you have and look for
$conf['auth']['checkip'] = true;
replace it with