Encrypting subjects in email

anybody know about when encrypting for subjects is gonna be ready? pls tell me if it already is because i cant find how to use it if its there somewhere. i read something about it from ~4-5 yrs ago and it said this would be worked on later. this would be good to have…thanks!

I don’t know if this would even be possible.

The message format defines the subject as an unstructured header field.

A client could theoretically put an encrypted string into it but would not have any way to indicate that to the receiving client.

Encryption of body (and attachments) works because the sending client can add data that indicates that the respective content was encrypted, which method was used and which keys.

The receiving client can then either use this to decrypt the content or at least show that it can’t.