If you, are any of your users, have issues logging in, make sure to use the email address as created in Jeto originally. The email field on the login page is case sensitive.
For example, if the email used to create the Jeto user is "Jane.doe@email.com", entering jane.doe@email.com will result in Jeto saying the user does not exist. The capital J is important.
NOTE: if you wish, Admins can update the email address in the Users tab of Jeto to reflect the desired format.