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Re: Language translation in e-mail standards

2000-11-13 10:23:38
I have made some tests on how some existing mailers (Eudora,
Netscape, Outlook Express, Hotmail, First Class, Pine, KOM 2000)
handle different ways of sending a message translated to
multiple languages.

The full test report can be found at
ftp://ftp.dsv.su.se/users/jpalme/draft-palme-multipart-language-00.txt

I started with the simple case of multipart/alternative with
one language version in each body part. None of the mailers
could handle this very well. Some mailers choose one
language part, some another part, but my impression was
that this choice was not made based on the language
preferences of the user for any of the mailers.

When none of the mailers seemed to be able to handle this
very good, I tried different more complex constructs.
But none of them works well with all the tested mailers.

A new extension to e-mail standards to handle language
translation should ideally degrade gracefully, in that
existing mailers will at least show the message in some
format readable to all recipients. None of the formats
tested worked OK with all the mailers.

The best format if graceful downgrading to existing
mailers is wanted, seems not to be multipart/alternative
but multipart/mixed. If this is used, however, each
body part should have a title with its language,
since some mailers just concatenate all body parts
with no divider between them. Thus, the format which
best gracefully downgrades for existing mailers is
the following format, note that the "****" lines have
to be explicitly inserted by the mailer.

    Message-ID: <language-test-7(_at_)dsv(_dot_)su(_dot_)se>
    Date: Wed, 12 Nov 2000 18:12:00 +0100
    From: Jacob Palme <jpalme(_at_)dsv(_dot_)su(_dot_)se>
    MIME-Version: 1.0
    To: jpalme(_at_)dsv(_dot_)su(_dot_)se,jptest(_at_)dsv(_dot_)su(_dot_)se
    Subject: Language test message no. 7 v1
    Content-Type: multipart/alternative; boundary="==boundary-2"

    Text displayed only to non-MIME-compliant mailers

    --==boundary-2
    Content-Type: text/plain; charset=iso-8859-1
    Content-Transfer-Encoding: 8bit
    Content-Language: en

    **** This message in English ****

    Message in English.

    --==boundary-2
    Content-Type: text/plain; charset=iso-8859-1
    Content-Transfer-Encoding: 8bit
    Content-Language: de

    **** Diese Nachricht auf deutsch ****

    Nachricht auf deutsch.
    --==boundary-2--

This is not very neat, but all other choices will downgrade
badly or very badly to some of the tested existing mailers.


--
Jacob Palme <jpalme(_at_)dsv(_dot_)su(_dot_)se> (Stockholm University and KTH)
for more info see URL: http://www.dsv.su.se/jpalme/