@ @THE_FRICKLER I don't use Grommunio in a business environment so do not receive many emails with Office document attachments so hadn't seen any errors as plain emails seem to be working OK. All html emails appear fine with all embedded graphics displaying correctly.
So I have sent myself a test email and can confirm the issues you have reported with Excel and Word documents not being correctly expanded. As you also report the emails open normally in Outlook, and with some lock issues in MacOS (v27) Mail (docs trigger Open Office but can only open in 'read only' mode).
Hopefully the devs can investigate and resolve this issue soon.