When you are finished with this step, your Gmail account still exists, but you do not see it in Outlook. If you receive any more emails at that Gmail account, you must repeat the steps in this article if you want them in your Office 365 mailbox.
- In Outlook, go to File > Account Settings > Account Settings.
- In the Account Settings window, select your Gmail account then choose Remove.
- In the dialog box about the offline cache being deleted, click Yes.
The Gmail messages that you imported to your Office 365 mailbox are still there, but your Gmail account no longer appears in Outlook.