When uploading users to the system via spreadsheet, the system does not automatically send account confirmation emails. If you decide that you would like to invite everyone into the tool at this point, go to the main Users page.
Select either all users or individuals using the checkboxes next to their name(s). Once you have selected at least one user, a small 'mail' icon will appear at the top of the page. Press this button to send the account confirmation email.