You may come across the error message "This email address has already been added." when you attempt to add your new Office 365 account to Outlook. This would occur if one of your old MyWork mail accounts shares the same name as one of your new Office 365 accounts. Please follow the instructions below in order to work around this issue. Please note: this guide is for Windows 7/8.1/10 machines.
Ensure that Outlook is closed before beginning.
1. Press the Windows key and start typing to search for "Control Panel".
2. Once in Control Panel, start typing "mail" in the top right (search bar). You will need to click on the "Mail" icon that appears.
3. In the "Mail Setup" window that appears, click "Email Accounts..."
4. Click "New"
5. Click "Manual setup or additional server types" and click "Next"
6. Select "Office 365", enter the full email address you are adding to Outlook, and click "Next"
7. A new window should appear prompting you to sign in. Your email address should be automatically filled - click "Next". If prompted, click "Work or School account"
8. You will be prompted to enter your password, and to sign in. Once you are signed in, the account will be added to Outlook.
If you come across the error message "Sorry, another account from your organization is already signed in on this computer", please follow this workaround for this issue.
For any other Office 365 setup issues, please submit a support ticket to firstname.lastname@example.org, and our support team will be in contact with you.