This document explains how to remove/delete an account configured for access withith Outlook for MacOS.
Important: The instructions below assume you have configured your account for Exchange/Office 365 and do not have any email data stored locally on your computer. If this is not the case, please make sure you have backed up your data before removing your account.
Start Outlook and navigate to the "Tools" tab at the top of the screen. Click on the "Accounts..." field from the drop down menu. In Outlook 2016 for Mac there will be buttons to choose from rather than a drop down menu. Select "Accounts" from the options.
After clicking the "-" button, you will be prompted as to whether or not you wish to delete the account. Click on "Delete" to delete the account: