The shared mailbox was created only for use as a mailbox, but it comes along with a calendar attached, which shows up in outlook.Use the Identity and Permanent parameters to disconnect the mailbox from the user, remove the user account, and immediately remove the mailbox from the mailbox database. Up till now, the only way to do this was to move or copy the emails from the Shared Mailbox to a Personal Mailbox and track the emails from there in Outlook.
It happens only on shared mailbox where user id is by default disabled on AD.
