How to change email address in user profile in ArcGIS Online?
You must have admin access. Go to the users profile:
Click on the "Edit Profile" button:
The option to change email it provided:
You can now change the Email addresses, or any attribute, of multiple users at one time using Admin Tools for ArcGIS Online. The tool will allow you to export all User Info to a CSV file where you can then make mass edits and import back in to ArcGIS Online. After the import, all changes will appear in your ArcGIS Online Org.
Retrieving data ...