@lanodan @xianc78 @nk I always just send ODF documents or ODS spreadsheets instead of DOC(X) or XLS(X) respectively.
Since they can be opened in Microshaft Office without problems (or at least they can be opened, I ASSume it's without problems, I never used that crapware before), so none of my clients even notice the fact it's not in a Microshaft Office format.