Prevent Outlook from Displaying Duplicate Gmail Tasks

How to use filters to avoid duplicate Gmail tasks in Outlook

If your Gmail email is set up in Outlook using IMAP and you flag emails in Outlook or star emails in Gmail, you may have duplicate items in your Outlook To-Do tasks list. These duplicates occur because Gmail displays the task in several folders such as All Mail and the Inbox. Outlook doesn't recognize these emails as being the same and shows multiple instances of the same task. Here's how to avoid duplicating tasks.

Instructions in this article apply to Outlook 2019, 2016, 2013, 2010; and Outlook for Office 365.

Make sure the To-Do Bar is visible in Outlook

Enable the To-Do Bar in Outlook before fixing the duplicate tasks.

  1. Go to the View tab and select To-Do Bar > Tasks.

    Viewing options in the To-do bar in Outlook.
  2. In the Tasks pane, select Arrange by > View Settings.

    Selecting the Arrange by options in Outlook.
  3. In the Advanced View Settings: To-Do List dialog box, select Filter.

    Viewing the advanced view settings in Outlook.
  4. In the Filter dialog box, select the Advanced tab.

    Viewing advanced options in Filters in Outlook.
  5. In the Define more criteria section, select Field > All Mail fields > In Folder.

    Choosing which field to filter in Outlook.
  6. In the Value text box, enter All Mail, then select Add to List.

    Adding a value before adding to the list in Outlook.
  7. The new filter appears in the Find items that match these criteria section. Select OK.

    The finished filter in Outlook.
  8. In the Advanced View Settings dialog box, select OK.

  9. Duplicate tasks are removed from the Task pane.

    Filtered results in Tasks in Outlook.