From: Charles Lindsey (chl@clw.cs.man.ac.uk)
Date: Wed Sep 25 2002 - 12:06:17 CDT
In <VyukqmClgZi9IAk4@pillar.turnpike.com> Ian Bell <ianbell@turnpike.com> writes:
>On Wed, 18 Sep 2002, Charles Lindsey <chl@clw.cs.man.ac.uk> wrote:
>>
>>It provides guaranteed 8-bit transport within bodies when 8BITMIME is
>>supported
>Not quite.
But almost.
>ESMTP guarantees that it will accept 8bit bodies;
Actually, I don't think the term "ESMTP" is used anywhere in RFC 2821.
>ESMTP servers may encounter non-8BITMIME servers on the next hop. But
>that's OK because they know how to convert 8bit MIME parts into 7bit
>MIME parts: leave headers alone as they're 7bit and encode leaf parts
>with qp or base64.
Indeed so, but hardly any servers do that conversion, even though they
claim to be 8BITMIME compliant.
But the whole point is that it is exceedinly rare to encounter a server
that does not support 8BITMIME in some form. Hence my claim that,
practically speaking, 8bit stuff in the headers of multiparts will get
through unscathed so often that it is hardly worth the trouble for a
gateway to worry about it (sadly, that is not true for such headers at
the top level, because of the sendmail problem).
-- Charles H. Lindsey ---------At Home, doing my own thing------------------------ Tel: +44 161 436 6131 Fax: +44 161 436 6133 Web: http://www.cs.man.ac.uk/~chl Email: chl@clw.cs.man.ac.uk Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K. PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5