In the logical image of my Apple device, all the emails are blank. What causes this?

Created by: Brendan Bone
Created date: January 26, 2015 20:33
Last Updated date: March 07, 2016 16:35

Full email messages can only be extracted in a physical image, because email is protected by iOS. When doing a logical extraction, iOS only allows access to the EnvelopeIndex database, which mainly tracks dates of emails, and no real message content.