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With the Outlook app open, select “File” at the top left:
In the File menu, select “Account Settings”:
In the Account Settings menu, select “Account Settings”:
In the “Account Settings” menu, Select “Data Files”:
On the “Data Files” tab, Select “Settings”:
In the Microsoft Exchange dialog box, select “Advanced”:
Highlight the Shared mailbox you would like to remove, and select “Remove”:
On the “Are you sure you want to remove this mailbox” dialog box, select “Yes”:
Select “Apply” to save the changes:
Select “OK”:
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Select “Close” on the Account Settings menu:
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