On Fri, 2 May 1997, Jon Morby wrote:
> My question is (assuming I'm reading this right), why did Exim attempt to
> send the message in 8 bit considering it wasn't told that the remote
> end could handle it?
Actually, Exim wasn't told that. Exim isn't designed as a protocol-
converting MTA. At present, it just sends HELO, not EHLO, since it has
no facilities for making use of the information it might get back - and
of course it was easier not to have to jump through the hoops necessary
to do the right thing for old servers out there that barf at EHLO in
various non-standard ways.
Given that Exim doesn't play protocol-conversion games, it made sense to
write it as an 8-bit clean program. There are many parts of the world
(particularly bits of Europe where accented characters are used a lot)
where 8BITMIME is not supported, and where doing anything to a message
that contains 8-bit characters probably renders it unreadable. I have
seen various flame-wars on the subject. It is clearly a "religious"
issue. [Crosses fingers and hopes we don't have another war here...]
This is the question that is discussed ad nauseam:
If an MTA has got a message containing 8-bit characters in its hand,
and it has no information about the place it is forwarding to, what
should it do?
The options are:
(a) Refuse to deliver the message,
(b) Munge the message into some 7-bit form, either MIME or "quoted-
printable" (aka "quoted-unreadable"),
(c) Just send it as 8-bit characters.
I am in the camp that believes (c) is the best action, as it is the most
likely to have the effect that the end users actually want.
[As an aside: I must admit I find it extraordinary that, after over a
decade of TCP/IP, which is and always has been an 8-bit transport, we
are still trying to push for 7-bit standards.]
I really don't want to clutter up Exim with MIME stuff - surely that is
really the province of the MUA?
Philip
--
Philip Hazel University Computing Service,
ph10@??? New Museums Site, Cambridge CB2 3QG,
P.Hazel@??? England. Phone: +44 1223 334714
