If you delete the Mailbox from Exchange, it will delete AD account associated with it. So administrators will get very often confused.
So we need to Run Disable-Mailbox to remove mailbox and Exchange properties which will not delete the AD Account.
To remove the mailbox
Run Disable-Mailbox -identity <Mailbox ID>
if you run, Get-Mailbox -Identity Administrator, You will get an Below Error as there is no Mailbox Associated with it
Now you will create another mailbox for the same user without any issues,
Open Exchange admin center–>Recipients–> Mailboxes–> Click on User Mailbox
Click on Browse
Select Administrator(Ad User)
Select the Mailbox Database
So we have seen how to disable mailbox and recreate the mailbox for the same AD User.