Using Outlook for Mac a user is sometimes unable to view the body of the emails.
It can occur in two ways
1. Nothing displayed at all in the body.
2. Partly missing with signature displayed.
Viewing same emails in Outlook for Windows / Webmail and body is visible.
Thought it might be something to do with content but one example was a basic system generated email sent by our support system, which on one occasion was fine, the other blank despite being exactly the same message.