ACE length in e-mail addresses (was: Re: [idn] I-D ACTION:draft-ietf-idn-uri-00.txt)

["Maynard Kang" <maynard@pobox.org.sg>]

> UTF-8 IDNs will cause trouble in this case. The point I'm making is that
> ACE IDNs will cause trouble too.
>
> UTF-8 IDNs will lead to additional non-821-compliant addresses in SMTP
> and additional non-822-compliant addresses in message header fields. The
> resulting 8-bit addresses are known to cause trouble for some programs.
>
> ACE IDNs will lead to additional non-821-compliant addresses in SMTP and
> additional non-822-compliant addresses in message header fields. The
> resulting long addresses are known to cause trouble for some programs.

Right, I agree both solutions are potential troublemakers. However I still
think that the negative implications of using UTF-8 IDNs will be more
far-reaching than using ACE IDNs.

Long addresses appear more tolerable than 8-bit addresses; as 821 speaks of
"to the maximum possible, implementation techniques which impose no limits
on the length of these objects should be used" in spite of stating a 64-byte
limit on local-parts and 64-byte limit on domain.

(An interesting side note: the latest incarnation of
draft-ietf-drums-smtpupd seems to provide for a new 255-byte limit on domain
but still keeps the 64-byte limit on local-parts. Maybe that should be
changed too. Anyway, this is a drums issue)

822 imposes no limits, I believe. There is adequate provision for the
folding of long header fields.

> My software doesn't have any trouble. Please learn to read. What matters
> is that it effectively lowers any limits that your software might place
> on address length.

My software doesn't either. I think we both mean "your" in a collective
sense, right?

> ezmlm and its variants send a huge amount of mail every day. Keep in
> mind that (1) qmail is running on a very active 10% of the Internet's
> SMTP servers and (2) automatic bounce handling, via these long return
> addresses, is one of the top ten reasons that people install qmail.

How about servers which are running sendmail and will fall over and die when
they see UTF-8? According to their site, Sendmail "handles an estimated 75
percent of the Internet's email traffic".

Actually I switched to qmail for a different reason, but anyway...

maynard