While technically email addresses are meant to be case-sensitive (https://blog.teknkl.com/email-addresses-case-sensitive-but-anyway/) the whole internet treats them as if the were not. Just today I was going to answer to a user who wanted to be deleted that we did not have them on the DB to begin with, until I realized they had typed their email with different caps in different places and I notice we do check our emails case-sensitively here. We don't elsewhere (our "is email in use" comparison does lower() for comparison) so we should change this here too.