Please follow below steps to configure view settings to bold or not bolder all unread messages automatically in a mail folder in Outlook.

1. In the Mail view, click to open the mail folder where you want to bold or not bold unread messages, and click View > View Settings.

2. In the opening Advanced View Settings dialog box, please click the Conditional Formatting button.

3. Now it opens the Conditional Formatting dialog box. Please click to highlight the Unread messages in the Rules for this view list box, and click the Font button. See screenshot:

4. The Font dialog box comes out. Please select Bold or Bold Italic from the Font style list box, and specify other formatting as you need.
Note: For not bolding all unread messages automatically, please select Regular from the Font style list box.

5. Click the OK buttons successively to close all dialog boxes.
And now all unread messages are bolded (or not bolded) automatically in the selected mail folder.

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