Maybe to make it more clear: Currently users are registering for example with Firstname.Lastname@domain.com but afterwards forgot that they used uppercase. Now they want to login with lowercase firstname.lastname@domain.com but it does not work because Kratos is not recognizing this as a valid mail address On the other hand side mails are normally not case sensitive outside of Kratos so I seems like a weird inconvenience for the user to always have to match his initial upper/lowercase of his email. see also https://stackoverflow.com/a/9808332