Disabling ‘Other Users’ and “Public’ / ‘Shared Folder’ Namespaces in the Web Client

This HOWTO is a follow-up on Disabling and Enabling Webmail Plugins in Plesk Premium Email and deals with suppressing the availability of the folders other users share with one another, or global public folders shared with the user.

To suppress the ‘other users’ and ‘public’ namespaces for a specific vhost, add the following to /etc/roundcubemail/webmail.example.com/config.inc.php:

<?php
    $config['imap_ns_other']    = FALSE;
    $config['imap_ns_shared']   = FALSE;

NOTE: At this point, it is recommended to also disable the ACL plugin.

Doing so exclusively in either one of the following applications is possible as well, through testing the constants defined in each of those applications. For example, to only disable shared folders in CalDAV, CardDAV and WebDAV, test for the constant KOLAB_DAV_VERSION:

<?php
    if (defined('KOLAB_DAV_VERSION')) {
      $config['imap_ns_other'] = FALSE;
      $config['imap_ns_shared'] = FALSE;
    }

Similarly, for Microsoft ActiveSync, use the KOLAB_SYNC_START constant.