So you tell me that the message body is ok with Norwegian characters, it's only the subject?
That would mean that outlook interpretes the charset only for the message body, but not for
the subject. So if you have characters with an ASCII value greater than 127, your mail
program requires to enclose it into

=?<charset>?B?+<text>?=

Do you know that the "B" is for? I would not like to "blindly" do whatever Mutt does, I
would like to understand it. If someone can point me to a document which describes this
properly, I could implement it.