Office 365 - Thunderbird - Removing an account
This document will show you how to remove an account from your Thunderbird client in Windows/Mac.
In the Mail Account Setup window, highlight the account you would like to delete and right-click on the account:
Click on Settings
In the Account Settings dialog box which opens, click on the account you want to remove then click on Account Actions at the bottom of the left-hand portion of the screen, and then click on Remove Account:
Click on OK to confirm the deletion of your account.
You will be returned to the Account Settings dialog box. Deletion is complete.