If, on the other hand, we enforce the ban and add the rule that message/partial
parts must be 7bit, the only feasible way to fragment such a message is to
encode all the parts individually and then break it all up into separate
message/partial pieces in strict 7bit. This minimizes the burden placed on the
defragmentation software. I think making life easier for readers is a good
thing and therefore I do not support lifting the no encoding rule on
I think this is pretty convincing. I still have the uncomfortable
feeling that we are doing unnecessarily bad things to ourselves in the
event that enough of the network adopts 8bit negotiation capabilities
that encoding to 7bit would be end-to-end unnecessary. After all, the
size expansion on encoding might easily imply needing extra message
pieces, which means more whole SMTP transaction sets. We've agreed that
those are a problem, even if a little more bandwidth isn't.
Would a way out lie in making this, logically, message/partial7 (I
don't especially object to retaining the current name)? One could then
footnote the possibility of message/partial8 in the future, given
appropriate transport support. or
provide message/partial8 with the proviso that it must be
transported over an 8bit path and that a message containing it may
not be converted to 7bit form by a gateway.
I suspect that this points out something else that ought to be on the
list (Greg, please add for discussion).
The subtypes of Message have the potential for significant impact on
MIME interoperability. I'm not convinced that one can add one and
guarantee zero impact (unlike, e.g., subtypes of text or application).
How would people feel about a prohibition on adding Message subtypes by
registration, requiring standards-track processing as modifications to
MIME (and, hence, due consideration of impact) for such additions?
My hunch is that it would provide us a lot of protection with little
Greg, if we agreed to this, it presumably falls under the umbrella of
restricting out things we decided we didn't adequately understand the
implications of. True?