When using the Upload Embed Widget, the creator of the Widget will have the option to require that users include an email address with their upload. However, these user emails are not included in User Activity Reports. You can find the Uploader email address in two locations:
In Box Preview:
If you are in the process of Previewing an uploaded file, click on the "Details" tab in the right rail. The Uploader will be listed under File Properties.
In the Folder and File Interface:
To locate the Uploader email in the Folder and File Interface, simply locate the file and you can find the email in the Uploader column.
Reporting on Upload Embed Widget Uploaders
If you would like to pull a full report of Uploader emails from a specific folder, please use our APIs to gather the required data. You will need to use the GET Folder's Items call to do so. If you have questions about this process, please contact Box Support and open an "API or Developer Question/Issue" case.