Email changes are handled by us, please e-mail firstname.lastname@example.org to update the email address. By clicking the settings icon in the list of users (the gear icon) you can, however, change both the first and last name. A user ID, which is not affected by the updates, is used to identify the user in the system.
Under People > Users, you can see if your employees are having issues signing in or an email address isn't working properly:
Please email email@example.com with the old and the new email address and we will update this for you.