Re: [ietf-smtp] Quoted-Printable-8bit
John C Klensin <john-ietf@jck.com> Tue, 30 March 2021 23:12 UTC
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Date: Tue, 30 Mar 2021 19:12:14 -0400
From: John C Klensin <john-ietf@jck.com>
To: John Levine <johnl@taugh.com>, ietf-smtp@ietf.org
cc: paul@pscs.co.uk
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Subject: Re: [ietf-smtp] Quoted-Printable-8bit
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--On Tuesday, March 30, 2021 18:09 -0400 John Levine <johnl@taugh.com> wrote: > It appears that Paul Smith <paul@pscs.co.uk> said: >> We dont either, but RFC 6152 (written in 2011) has the text >> that [if the server does not advertise 8BITMIME support]: >> >> "then the client SMTP must not, under any circumstances, >> attempt to transfer a content that contains characters >> outside of the US-ASCII octet range (hex 00-7F)." >> >> This seemed quite a strongly worded requirement, so we'd made >> the decision that that requirement made it too complicated >> to handle gracefully, and as it was so strongly worded, we'd >> better not ignore it. >> >> But, if people are ignoring that requirement, it's actually >> interesting. Not because people aren't following the >> standards, but that suggests that 8BITMIME isn't actually >> that widely used... > > I think you're right. If your user base speaks English, it is > not likely to be sending around a lot of text where 8BITMIME > would help, and binary data is all sent as base64 because as > we have seen, the 25% bloat hasn't been enough to invent > something like quoted-unprintable. > > For really large stuff, people use Dropbox and its competitors. I don't have a strong position on the 8BITMIME question itself, but, as people think about changing or ignoring the requirement, they should probably keep in mind that SMTPUTF8 (RFC 6530ff) require 8BITMIME, i.e., advertising SMTPUTF8 without also advertising 8BITMIME is invalid. That is, of course, consistent with the 6152 requirement quoted above because one cannot comply with RFC 6531 and 6432 without transmitting non-ASCII header field material and... john
- [ietf-smtp] quoted-unprintable ? John Levine
- Re: [ietf-smtp] Quoted-Printable-8bit John Levine
- Re: [ietf-smtp] quoted-unprintable ? Russ Allbery
- Re: [ietf-smtp] quoted-unprintable ? John R Levine
- Re: [ietf-smtp] quoted-unprintable ? Ned Freed
- Re: [ietf-smtp] quoted-unprintable ? Tony Finch
- Re: [ietf-smtp] quoted-unprintable ? John R Levine
- Re: [ietf-smtp] quoted-unprintable ? Viktor Dukhovni
- Re: [ietf-smtp] quoted-unprintable ? Ned Freed
- Re: [ietf-smtp] quoted-unprintable ? John R Levine
- Re: [ietf-smtp] quoted-unprintable ? Gene Hightower
- Re: [ietf-smtp] quoted-unprintable ? Ned Freed
- Re: [ietf-smtp] quoted-unprintable ? Viktor Dukhovni
- Re: [ietf-smtp] quoted-unprintable ? Viktor Dukhovni
- Re: [ietf-smtp] quoted-unprintable ? John Levine
- Re: [ietf-smtp] quoted-unprintable ? Gene Hightower
- [ietf-smtp] Quoted-Printable-8bit Gene Hightower
- Re: [ietf-smtp] Quoted-Printable-8bit Viktor Dukhovni
- Re: [ietf-smtp] Quoted-Printable-8bit Sam Varshavchik
- Re: [ietf-smtp] Quoted-Printable-8bit Jeremy Harris
- Re: [ietf-smtp] Quoted-Printable-8bit Viktor Dukhovni
- Re: [ietf-smtp] Quoted-Printable-8bit Gene Hightower
- Re: [ietf-smtp] Quoted-Printable-8bit Gene Hightower
- Re: [ietf-smtp] Quoted-Printable-8bit John Levine
- Re: [ietf-smtp] Quoted-Printable-8bit Sam Varshavchik
- Re: [ietf-smtp] Quoted-Printable-8bit John Levine
- Re: [ietf-smtp] Quoted-Printable-8bit Gene Hightower
- Re: [ietf-smtp] Quoted-Printable-8bit Paul Smith
- Re: [ietf-smtp] Quoted-Printable-8bit Jeremy Harris
- Re: [ietf-smtp] Quoted-Printable-8bit Hector Santos
- Re: [ietf-smtp] Quoted-Printable-8bit Sam Varshavchik
- Re: [ietf-smtp] Quoted-Printable-8bit Paul Smith
- Re: [ietf-smtp] Quoted-Printable-8bit Ned Freed
- Re: [ietf-smtp] Quoted-Printable-8bit Dave Crocker
- Re: [ietf-smtp] Quoted-Printable-8bit John R Levine
- Re: [ietf-smtp] Quoted-Printable-8bit Ned Freed
- Re: [ietf-smtp] Quoted-Printable-8bit Gene Hightower
- Re: [ietf-smtp] Quoted-Printable-8bit Jeremy Harris
- Re: [ietf-smtp] Quoted-Printable-8bit John C Klensin
- Re: [ietf-smtp] Quoted-Printable-8bit John R Levine
- Re: [ietf-smtp] Quoted-Printable-8bit Viktor Dukhovni
- Re: [ietf-smtp] Quoted-Printable-8bit John C Klensin
- Re: [ietf-smtp] Quoted-Printable-8bit Viktor Dukhovni
- Re: [ietf-smtp] Quoted-Printable-8bit Tony Finch
- Re: [ietf-smtp] Quoted-Printable-8bit and downgra… John Levine
- Re: [ietf-smtp] Quoted-Printable-8bit and downgra… Viktor Dukhovni
- Re: [ietf-smtp] Quoted-Printable-8bit and downgra… Ned Freed