Tried the beta it is still not working, when trying to load from bytes mime signed email, it actually cannot even load regular fields it was able to load before, like sender or subject. I am talking about CreateFromEml method. Also as a result (maybe) NeedExtraction property is false. While on not netstandard it works great and populate all properties as well as NeedExtraction. If you still force it to decode manually, it tells you malformed. BTW it is all done like in the sample by disabling AutoExtract and verifying need for extraction and encrytption. Let me know if you need sample eml