Hi Jussi,
You may find this link helpful: https://www.targetprocess.com/guide/settings/users-roles-permissions/create-new-user-account/?highlight=
Yes, users can be added via an email address -- which email address shouldn't technically matter. Whether a license exists would seem to be the constraint.
As for user type I think you are referring to a user role. Roles can be configured/created by your enterprise Targetprocess admin, with no restrictions that I'm aware.
Best, Tom
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