If I remember the discussions correctly, there were a couple of
differences between "8bit" and "binary":
To quote RFC 1521:
"8bit" means that the lines are short, but there may be
non-ASCII characters (octets with the high-order
bit set).
"Binary" means that not only may non-ASCII characters
be present, but also that the lines are not
necessarily short enough for SMTP transport.
It is my belief that a single-body message encoded in 8bit MUST have
its last bytes be CRLF in order to be sent using the 8BITMIME SMTP
extension; this makes the behaviour of PD Eudora, which labels attachments
as "Binary" and sends them using SMTP, rather questionable in my eyes.
(But not more so than the behaviour of "mhn" in MH 6.8, which refuses to
recognize "binary" as a valid C-T-E.....)
I would like to have the "must end in CRLF" requirement on 8bit be
explicit somehow; also, mentioning lines at all in the section on "Binary"
ought to be deleted; what is a "line" of audio?
But I'm not going to die on its behalf, or even spend
much time arguing. Have fun - make systems work, folks!
Harald A