Re: [ietf-822] utf8 messages

[Mark Martinec <[e-mail]>]

2014-08-12 10:20, Brandon Long wrote:
> So, if I have an "email" message, I can no longer just parse it.
> Instead, there are actually two
> types of email messages, and the only way to know how to parse it
> is to know a priori which type it is.
> Because all systems are "sealed" and there's never any leakage.
> [...]
> Yes.  And the most obvious place for that information, to me, is in the
> headers of the message.  Assuming that every mechanism for exchanging 
> email
> messages needs an explicit external piece of data...

Actually the presence of an SMTPUTF8 flag *is* reflected in the
header section of a message. It's in the WITH subfield of a
(likely topmost) Received header field (RFC 6531), as inserted
by your MX or MSA:

   UTF8SMTP	ESMTP with SMTPUTF8
   UTF8SMTPA	ESMTP with SMTPUTF8 and AUTH
   UTF8SMTPS	ESMTP with SMTPUTF8 and STARTTLS
   UTF8SMTPSA	ESMTP with SMTPUTF8 and both STARTTLS and AUTH
   UTF8LMTP	LMTP with SMTPUTF8
   UTF8LMTPA	LMTP with SMTPUTF8 and AUTH
   UTF8LMTPS	LMTP with SMTPUTF8 and STARTTLS
   UTF8LMTPSA	LMTP with SMTPUTF8 and both STARTTLS and AUTH

http://www.iana.org/assignments/mail-parameters/mail-parameters.xhtml#mail-parameters-7

(and equivalently for LMTP)

> Is there a separate three letter filename extension for 6532 messages,
> for example? (for platforms which use such things).

RFC 6532:
   message/global -> .u8msg

RFC 6533:
   message/global-headers -> .u8hdr
   message/global-delivery-status -> .u8dsn
   message/global-disposition-notification -> .u8mdn


Mark