Thank you. That will help greatly, needless to say Decrypt etc is also missing from IMail, they are private on MimeDocument though. But one more question, I didn't test certificates stored on machine, since we only have secrets done in kubernetes, but why builder.SMIMEConfiguration.Certificates.AddRange(certificates); doesn't help with automatic decryption? I would expect it to have similar effect? Lastly, the versions between download and latest nuget are different. Is there schedule reason for it?