One observation about binary transport in mail.
I am the principle developer of IMAP (RFC-1176) based software. I wrote most
of the extant IMAP software. I've been evolving IMAP to fit in with RFC-XXXX
and its brave new world (I wish I could get RFC-XXXX cast in stone so I can
get my IMAP extensions cast in stone!!).
I tried implementing binary in IMAP; that is, converting BASE64 into its 8-bit
form and transmitting that. IMAP already uses counts. It's based on top of a
reliable stream such as TCP. And I wrote *all* the software in question.
I had *terrible* interoperability problems. It took forever to nail down
problems. The cost of getting out of synch with binary is much worse than
that for plain text.
I won't even go into the machine-dependent questions. Some topics are not
proper to discuss in mixed company. ;-)
Eventually I threw in the towel. IMAP uses BASE64. The problems went away.
If a (presumably) intelligent and experienced implementor has interoperability
problems in instances of his own software, what sort of problems might exist
in the harsh world of real-life implementations? Look at all the people who
still can't get Telnet or SMTP right.
Call me an old fart if you like, but I'd rather flatulate than suffer endless
cramps.