Should there be a user in the deleted users view such as email@example.com
An admin will not be able to provision another user with the same name/address.
However the admin would be able to provision a new user Doe John with address firstname.lastname@example.org
This results in confusion and NDRs when attempting to mail the newly provisioned user from within the same org -
ibm-ndShortName mail server router operations would cause this conflict
Note: Mails from outside the Org are delivered to the newly provisioned user