Sometimes when you have users leave the Microsoft 365 platform other users need access to their email for a time, this is accomplished by giving permission for them to have full access. Unfortunately this process doesn’t have a UI option to disable automapping so once they have access their Outlook desktop client gets bogged down with double the emails and storage size potentially. This can create a miserable experience for the User. They still want access just not forced inclusion on Outlook. The normal method of close account via Outlook will not work. You have to go to the PowerShell and run three lines and commit them one at a time.
Line #1: Loginto Microsoft 365 vis PowerShell, this will require Admin login and password
connect-exchangeonline
Line #2: Remove Full Access for the User
Remove-MailboxPermission -Identity emailneedingaccess@domain.com -User userneedingaccess@domain.com -AccessRights FullAccess
Line #3: Readd the User with AutoMapping turned off
Add-MailboxPermission -Identity emailneedingaccess@domain.com -User userneedingaccess@domain.com -AccessRights FullAccess -AutoMapping $False
