You have a few options, emails are not needed!
-If you use Google Classroom, Edmodo, or Canvas, you can upload your rosters straight into OpenEd with the click of a button. Just go to your Roster tab on OpenEd and you will see "upload using..."
-For middle or high school students, we suggest giving them a class code so they can sign up independently. Your class code is available on the Roster tab.
-For younger students, you can create a username and password for them, or upload all your students in a Microsoft excel CSV spreadsheet, also from the roster tab.
-You can also use students' emails to invite them, an option that is only availble to high school students.