How does a user reset their email password

Like the subject says, how do my email users change their email password. So far the only place that I can find for password maintenance is in the mail admin page, which allows whoever can get there to create, delete, or modify all accounts. I certainly don't want that, nor do I want to have anyone except the actual user of the account to know the password. I could not find it in Preferences, which is where I expected int. Isn't there somewhere in Roundcube Webmail user interface where an individual can change the password for their account?