When we need to delete a user in Microsoft 365, There is an option to make the mailbox into a shared mailbox. You will not be able to login to that mailbox anymore, instead after converting the user mailbox to a shared mailbox, you can delegate another user with permission to that shared mail box.
optional step: When we delete a mailbox, by default the alias of that mailbox is deleted. If you want to delete the email address of the user (ie., email@example.com) we need to change the current mail address to an alias. And make the current Microsoft default alias (firstname.lastname@example.org) as the primary email.
select user==> account tab ==> click on “manage username and email” ==> under aliases click on the 3dot menu ==> select “change to primary email” (this will make Microsoft default alias to primary email address).
To delete a user:
- select user from active users list ==> click on delete
- Tick “email aliases will be removed”
- Tick “Give another user access to access to <user>’s email.”
- click on “required:Give email access to another user”
- Assign another user to the mailbox.
- Click on Delete user.
- Select create a new display name , and set a Display name for the shared mailbox.
- if you don’t want to send automatic replies. Untick send automatic replies dialogue.
- Click on transfer ownership.
- click on assign and convert.