This info helps if you're looking to modify the amount of data used by your personal email account.
From a Home screen, navigate: Apps icon > Email.
Tap the Menu icon (located in the upper-right).
Tap Settings.
If applicable, select the desired email account (located on the left).
Tap More settings.
From the Common settings section, edit any of the following: The available settings may vary depending upon the email account type. Enabled when a check mark is present.