We are a single server Exchange 2010 shop with a mix of Outlook 2013 and Outlook 2010 Clients.
A set of our users has historically created an email, saved it in their drafts, and then drug (ie saved) the file out to a set of specific folders on the network (emails related to a given job).
Later, they open the saved email directly from its file folder on the network and Send it. Historically, this has worked great.
As of this morning our Outlook 2013 clients all have the same problem - the email arrives, with subject, addressees, and attachments intact, but with the body of the email totally missing. It happens across a wide variety of user accounts and base OSes, including Windows 7, Windows 8, and Windows 10.
The problem does not seem to happen on Outlook 2010 Clients.
That same email, if it still exists in the drafts folder, can be sent, in which case it arrives fine and fully intact.
It doesn't seem to matter if the files are saved on the network or on the local hard drive.
The computers have been rebooted.
This process was working as recently as yesterday without issue (as evidenced by emails in the sent folder which are not blank).
That said, we did install 22 Updates on 8/26 to the Exchange server. Being a huge fan of did it ever work, when did it stop working, and what did you do right before that, one of them seems the most likely culprit. Some searches on Google, etc have not returned any obvious writeups about the problem. The only update actually related to the Exchange server is the antispam filter updates. The rest are general 2008 security updates, IE updates, etc.
Looking in message tracking in Exchange, the email that arrives blank at the destination is noticeably smaller in size, so whatever stripping of the body that is happening appears to be BEFORE it arrives at the server.