RE: SMTP and unicode

From: Dean Harding (
Date: Tue May 17 2005 - 18:10:11 CDT

  • Next message: Hans Aberg: "RE: SMTP and unicode"

    Almost all mail servers I've ever encountered (at least, those that support
    the ESMTP protocol) support the 8BITMIME extension (see which lets you send 8-bit
    MIME-encoded data. (By the way, you'd generally still need to send messages
    encoded as MIME whether you're sending it as 7-bit or 8-bit).

    Personally, I've never bothered using the extension, because it means you
    have to query the MTA you're sending to before you can encode your message
    to see if it accept 8-bit MIME messages. I've always just found it's
    simpler to encode the message using a 7-bit scheme and forget about 8-bit
    (after all, you need to write the 7-bit fall-back method anyway).

    I guess that's why 7-bit isn't going to go away: people like me are too lazy


    -----Original Message-----
    From: [] On
    Behalf Of Hans Aberg
    Sent: Wednesday, 18 May 2005 6:29 am
    To: Stephane Bortzmeyer
    Cc: faraz siddiqi;
    Subject: Re: SMTP and unicode

    At 21:53 +0200 2005/05/17, Stephane Bortzmeyer wrote:
    >The default channel in SMTP is only 7-bits wide, for historical
    >reasons. Almost all the SMTP servers, for many, many years, accept to
    >properly carry 8-bits data (wether UTF-8 or else). See RFC 2821, "2.4
    >General Syntax Principles and Transaction Model".

    When 8-bit mail servers started to appear in the beginning of the
    1990'ies, it probed difficult to ensure that all servers the mail was
    passed through were 8-bit. Thus, using an 8-bit character encoding,
    the mail frequently got corrupted. Therefore, people switched to
    MIME, which encodes 8-bit data into 7-bit data. That situation seem
    to remain.

    One should find a method to kill of any mail servers that still
    zeroes out the 8'th bit. Then one can send UTF-8 mail without using

       Hans Aberg

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