Dear all, Barry Caplan had written:
SMTP [...] is not 8 bit clean. It is very clear in the RFCs that only 7bit data is allowed "over the wire".
Stephane Bortzmeyer wrote:
All these extensions are referenced in the same RFC, 2821, which is the authoritative one about SMTP.
As of November 2002, RFC 2821 is still a Proposed Standard, and RFC 821 is the Standard Protocol (cf. <http://rfc.sunsite.dk/rfc/rfc3300.html>).
The most important for us is 8BITMIME:
Section 2.3.1 of RFC 2821, the proposed standard, says: | The content is textual in nature, expressed using the US-ASCII | repertoire [1]. Although SMTP extensions (such as "8BITMIME" [20]) | may relax this restriction for the content body, Stephane Bortzmeyer quoted section 2.4 of RFC 2821: > Eight-bit message content transmission MAY be requested of the server > by a client using extended SMTP facilities, notably the "8BITMIME" > extension [20]. 8BITMIME SHOULD be supported by SMTP servers. "SHOULD" does definitely not mean the same thing as "MUST". An SMTP server does not have to support 8-bit MIME mail. And the remainder of the quoted paragraph requests proper MIME headers for 8-bit text: | However, it MUST not be construed as authorization to transmit | unrestricted eight bit material. 8BITMIME MUST NOT be requested | by senders for material with the high bit on that is not in MIME | format with an appropriate content-transfer encoding; servers | MAY reject such messages. Barry Caplan had written:
But for arbitrary email from one address to another, you can't rely on it.
Stephane Bortzmeyer wrote:
I send Latin-1 (ISO 8859-1) emails for more than ten years (and without using quoted-printable or other similar hacks) to French-speaking people in various parts of the world and I'm still waiting for an actual problem.
Mere luck, I'd say, but no proof at all. I have seen many messages, originally in ISO-8859-1-encoded French, that got the high-bit of every accented character chopped off, thus replacing "é" with "i", "î" with "n", and so forth. And even more mail in German, distorted in a similar way. This has provoked an entry in my E-Mail FAQ: <http://www.systems.uni-konstanz.de/EMAIL/FAQ.php#SMTP-73>. Of course, more and more SMTP servers support 8-bit MIME, and many take the pains to transform 8-bit MIME to some transfer-encoding supported by the receiving server. If you are located behind a server that recodes your 8-bit mail, you cannot claim that 8-bit mail is supported everywhere; you can only claim that your server compensates for the incompatibility of your MUA and the world at large. Best wishes, Otto Stolz
