If you’re using Hestia CP to host your Roundcube email client and you cannot update your email password, then you’ve come to the right place.
In my case, there is a little configuration to enable password updates. That configuration is to update:
$config['password_hestia_host'] to your current domain name under which your email address sits.
To do this, go to /etc/roundcube/plugins/password and edit the file config.inc.php
Find the configuration line above, it may sit down at the bottom of the file content, and replace the host.domain.com argument.
However, never forget to back up the default configuration before you do that.