Over on another list we have been musing about CHUNKING and BINARYMIME.
CHUNKING is easy to implement (I added it to my MTA in about an hour) but
is extremely painful on systems where the native line ending is not \r\n
have to parse MIME bodies to figure out when to change line endings and when
The advantage of BINARYMIME over base64 is that base64 is 33% bigger since it
six bits per octet rather than 8. It occurs to me that since everone these days
supports 8BITMIME, one could invent a quoted-unprintable encoding that encodes
the characters that are special, CR LF NUL. (To play it safe I'd also encode
This gets you about a 2% size increase and stays compatible with 8BITMIME.
This seems totally obvious. Has anyone proposed it before?
I realize that there is a severe chicken and egg problem here since you
wouldn't use it
unless you knew your recipient could handle it. I suppose one could add an
but MTAs don't downgrade on the fly any more, particularly since that means
they would have
to redo DKIM and ARC signatures.
PS: I also realize that the sensible way to send a message with a giant
to put the attachment on a web server and use message/external-body, but that
all that well supported, either.
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