If you use Symbolics Zmail, you've had the ability to use multiple
fonts, languages, even diagrams in your mail. But after being flamed
by crippled readers who couldn't handle it, I avoid all use of multiple
fonts in mail.
Yes, I've been worried about the same thing. In particular, I don't
think anyone (well, perhaps a few radicals) at PARC will want to send
formatted messages to a mailing list, just because the opacity of the
list will prevent them from knowing who they might be offending. As
I've noted before, our gateway from XNS mail (which supports formatting
and pictures and attachments) throws away anything but ASCII text
(actually XCS text) when converting to SMTP addresses -- and that seems
to be the right design decision, at least given the state of UNIX
It almost seems that for the gateway to do the right thing, there needs
to be a database of addresses, and whether each address is or is not
willing to accept formatted mail. But that's a terribly messy problem...
It does sound suitable for phasing in the standard as a whole,
however; it should be easy for old-fashioned readers to just
read the first ascii part, and punt when they come to the
unreadable version. (Which argues for it being better to pick
the *LAST* version you can handle, so the dummest reader can
just show the user the bare ascii version up front).