User isn't able to create a new user in DeepSight using their e-mail address.
Email Already Exists
Usernames are unique in DeepSight, so they can only be used once. If a user is deleted, a new user can't be created with the same e-mail address.
If a user is no longer authorized to use DeepSight, it is preferable to deactivate the user, if there is a chance that user will need to be reactivated in the future.
If it has already been deleted, a new user can be created with another username, as long as it is in e-mail format.
If a deleted user must be recovered, please create a case with technical support. A request can be made to DeepSight Engineering to recover it from the database.