Ken Murchison <[EMAIL PROTECTED]> writes: > I find it interesting, if not disturbing, that some members of the > usenet community seem to think that mail messages and usenet articles > are not the same thing. AFAICT, from reading the relevant standards, > writing server code for SMTP/LMTP/IMAP/POP3/NNTP, and everyday use, mail > messages and news articles both conform to RFC 2822 (RFC 1036 states as > much). The only differences that I'm aware of are the following:
> - usenet puts a greater restriction on the headers (although still being > RFC 2822 compliant) Yes, although there are a variety of subtle things that fall into this category that one has to be careful of. That's one of the difficulties with Dan Kohn's existing draft; in dropping all of the language that was completely unnecessarily copied from RFC 2822, he's also dropped some language that's actually necessary. Usenet's restrictions on the syntax of message ID headers are very specific and very precise, and much stronger than those of RFC 2822, in part because message IDs are used as part of the NNTP protocol. Comments in various places that mail supports them are not well-supported by currently deployed Usenet software (although it certainly hurts nothing to support them when writing new code, other than adding complexity). The space after the colon in headers is not optional on Usenet. The syntax of the Date header is restricted in ways somewhat similar to that of the Message-ID header. > - mail messages are typically tranmitted over a 1-to-1 protocol (SMTP) > and news articles are typically transmitted over a 1-to-many protocol > (NNTP) > Could somebody please enlighten me as to any others differences, > perceived or otherwise? - National 8-bit character sets are in widespread use in Usenet message headers, possibly more widespread than they are in (non-spam) mail messages. Untagged 8-bit national character sets are widely used in various non-English hierarchies in headers as the preferred way of including such content, and in some cases use of RFC 2047 is frowned on. Usenet was able to get away with that when e-mail couldn't because the Usenet core software has always been 8-bit clean and because, due to the more centralized nature of Usenet, it's possible to make determinations like "every group in this hierarchy will be using this national character set" and even encode them in news clients. It's much harder to know what character set to expect in the general case in e-mail software. - MIME never got very much uptake on Usenet for attachments. The binary newsgroups are almost universally uuencode or, these days, yEnc. Base64 is rather rare and not at all popular. Binary readers and posters, for reasons that I admit to really not understanding, seem to have had no interest in the additional, cleaner semantics offered by MIME attachments and continue to be happy with uuencode, scanning the body for telltale lines, and doing guessing based on file names. Part of this may be due to the fact that much of the Usenet binary traffic is split across multiple posts and the MIME message/partial content-type is ill-suited to Usenet for a wide variety of reasons. Just splitting a uuencoded file into multiple parts is a lot easier (although it certainly makes decoding a pain). -- Russ Allbery ([EMAIL PROTECTED]) <http://www.eyrie.org/~eagle/>
