There is an identified issue within the new Microsoft update KB4011626. Microsoft is aware of the issue and describes the update and problem in this January 9 support memo.
In short, all attachments are being stripped from forwarded emails. Some of our CMPS users have contacted us however this is not exclusive to those scanned from our Xerox devices. A recommendation if scanning to email using the Xerox MFD is users can add all the recipients at the time of scanning. That way everyone receives the document directly from the Xerox device. This prevents users from having to forward the document as an attachment from their Outlook.