User is experiencing odd issue when opening emails in sent folder

I originally posted this in the O365 for Mac forum, they recommended that I move it here. One of my users is having a bizarre issue where when she opens an email that she has already sent (from the sent folder), it opens it as if it was in the drafts folder. She can edit the email, and send it again (it comes through as 2 separate emails obviously). Any ideas why it is doing it, and even more pressing, any ideas on how to fix it?

Below is a (redacted) screenshot showing what she gets when she opens the email

Details (taken from original thread):

1. Office Version: 2011
2. Office Revision: 14.5.5 (150821)
3. Account is an O365 E3 Exchange Acct
4. Does not happen in OWA
5. Only happening for this user (all emails when opened from sent folder)
6. Yes, emails are sent out the first time.