When importing new data into System Administration, there are certain validations that will run to make sure that existing data is not adversely affected.
If there are inconsistencies between existing data and the data being imported, an error message will be displayed that will identify the error along with the file location of the data that was rejected.
Such errors ...
System Administrators have the ability to edit user email addresses as needed. This may also require users to re-create their password.
Manually Updating a User's Email Address
Enter System Administration:
On the left-hand menu, select "People"
Search to locate the user whose email address requires updating.
To the right of the user’s name, click the Menu icon to acce...