Hi again!
Sorry to insist, but I think you're confusing the encoding of the BODY with the encoding of the SUBJECT.
I searched Mail and there's no encoding parameter for the Subject (there's for the body).
I downloaded the v2.7 trial and I have the same issue with the Subject. In fact I see the coding in the subject email when registering to this site (I think you're using the new version, right?). I can fowared the email to you if you like.
One more thing, I see that using zimbra webmail.
Thanks!