If you view your messages in multi-line layout, you can quickly arrange messages by attachment by clicking Attachments on the Arranged By shortcut menu.
How you tell Outlook to arrange messages depends on whether you view your messages in multi-line layout or in single-line layout.
The example here shows multi-line layout. Click Play to see how to group messages by attachment in this view. If you view your messages in single-line layout, see the next page.