Someone in the UK told me that he occasionally uses a "Grey Book"
mailer. Apparently, this mailer simply does not allow headers other
than stuff like From:, To:, Reply-To:, and Authorising-User:. I.e. no
MIME headers allowed.
Grey Book, or the JNT protocols, are a rather different kettle of fish. There
are such substantial differences in the header format specified by the Grey
Book (e.g. domains are written in the opposite order) that it really isn't
possible to view this format as RFC822-compatible. (Yes, it is apparently
derived from RFC822, but you could say the same thing about Novell MHS.) In
particular, the actions associated with the conversion of RFC822 messages to
Grey Book format very much depend on comprehensive knowledge of headers and are
therefore the actions of a gateway, not a simple MTA. This task is closer to
the conversion of MIME to X.400 than anything else.
But he says that he is sure that the gateway(s) to the Internet would
use a standard way of getting around this if there was one. So it
seems to me that it would make sense to write up a spec that *all* of
the people in similar situations (i.e. not only "Grey Book", but every
other system with such problems) could use the same method, and
*should* such stuff *ever* spill out of those enclaves, well,
high-quality, commercial UAs will probably do "the nice thing" for the
human receiver.
The problem of converting MIME to Grey Book format can only be solved by
first figuring out a way to represent multimedia mail in the Grey Book world.
Only after this is done is it appropriate to talk about gateway specifics.
There are various ways this could be done:
(1) The formats are close enough that MIME could probably be adopted with
very few changes.
(2) Some type of encapsulation could be defined for various multimedia formats.
(3) Something completely new and different could be invented.
It is not appropriate for us to make this choice -- it is something that Grey
Book users and developers have to decide for themselves. The only circumstance
under which I would think unilateral action on our part would make sense is if
the Grey Book community declined to deal with this issue.
If we *did* write such a spec, it would help if we could publicize it,
like, *really* widely, by actively going out and searching for
environments that would have these problems. So, does anybody know
of examples other than "Grey Book" mailers that have this problem?
I don't have a problem with coming up with solutions to problems. I do have a
problem with the imposition of these solutions on other communities. We can and
should provide solutions and even make recommendations. In the case of Grey
Book, I'm not sure we have enough knowledge to even make a reasonable
recommendation; there are simply too many choices.
Ned