In our team we faced with an issue, when a team member created the account but made a mistake in the email address that is used as login. In half of the year, the team member forgot the password to the account and wasn't able to restore access due to this mistake. As the result, the access to the account couldn't be restored even with the help of Mentimeter support team and all the presentations were lost :( I think, that would be great to add email verification when new accounts are created, that can help avoid such issues in future.