Article ID: 980540 - View products that this article applies to.
Consider the following scenario:
In this scenario, the email messages that are selected are fully downloaded. The email messages that are not selected remain as header-only messages.
To work around this behavior, turn off the People Pane. To do this, click People Pane in the People Pane group on the View tab, and then click Off.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.