I have loaded my Excel spreadsheet with class names, addresses and email addresses. It appears the names are all there, but when I wanted to send an email to all classmates, I'm finding many of the email addresses that were entered on the spreadsheet are not on the site. Could you tell me why this might happen? Do I need to manually add all of the missing email addresses?

Oh! I know what I did! I left out the second street address column, so now everything is one column off. I can just re-send the whole spreadsheet, right?

You'll have to do a reset to overwrite anyone that is already in the system. If anyone has logged in and created a profile you'll want to exclude them from the overwrite when the confirmation page comes up.

Will the yearbook photos be affected by this edit?

Yes, any Classmate you reset will also delete the Yearbook Photo.