As of last week, customers began calling in with problems where when they scanned a PDF to their email it would result in a multi-part MIME message and instead of the attachment they would get loads of gibberish within the body of their email.
This is a known issue caused by a recent Microsoft update that has yet to be addressed by them. However, in speaking with the hotline today they offered the workaround below, I have not tested it yet but will be later today.
User Tools>Scanner Features>Send Settings>Compression (Gray Scale/Full Color) lower to Level 1, Set High Compression PDF Level to Standard