Shared mailboxes in Office 365 is a great way to save costs since you don’t need a license and can be shared amongst 1 or more licensed users. When giving permissions to shared mailbox, Outlook will automatically add it your mailbox view like this:

While sometimes it’s convenient, there are times where you don’t need access to it all the time, especially on a travelling laptop. So to remove the auto map, simply connect to your Office 365 (Exchange Online) via powershell.

Then run the following command:
Add-MailboxPermission “SHARED-ALIAS” -User “USER-ALIAS” -AccessRights FullAccess -AutoMapping $False
Of course you can still access the mailbox by manually adding it in Outlook or opening the shared mailbox via the Outlook Web Mail interface.