A family of Microsoft word processing software products for creating web, email, and print documents.
I had the same problem and I manage to solve it.
In my configuration, Outlook was set up with multiple accounts.
One Microsoft Exchange account and 4 different IMAP/SMTP accounts.
When I was using one of the IMAP accounts as the default, this bug occurs every time I share a document from office. Please note that in my case, losing the text content was part of the bug, in addition, the mail got saved into the exchange account sent folder, yet having the from address appearing as @gmail looking at the saved mail.
Even if I change the "send from" address before sending the email the result does not change. Empty body, and saved in the wrong sent folder.
Changing back to Exchange as the default sending account, everything goes right. Body is not lost, and the mail is saved into the "sent" folder of the actually used account chosen from "send from" address. I mean, I can still send using the IMAP account, but it's not proposed as the default.
Hope this help understand the cause of the bug and solve the problem.
Bye,
Antonio.