If you have a property panel with an automated feed in your email, you can choose how many properties you would like to show.
To change this, firstly make the panel active by clicking on it.
Click the Define Properties button found in the middle of the active panel.
You will then see a pop-up with 3 tabs - Basic, Advanced, and Feeds
In the Basic tab, go to the Maximum Properties drop down (1), and change your selection to suit (there is a maximum of 48 properties).