Open web browser, go to the login page Rackspace webmail with the help of this link:- https://apps.rackspace.com/index.php
Enter the button of forgot password which is present on the Rackspace webmail login page.
Enter the email address in the given text field and enter the button of next.
Rackspace will send a email with a link for reset a password.
Enter a new password and retype a new password for confirmation.
Enter the button of reset password in your Rackspace webmail account.
See Also this post:- https://datarecovo.hpage.com/steps-to-log-in-apps-rackspace-com-webmail-account.html