technically speaking, SMTP clients that send 8bit messages without
seeing the proper 8BITMIME EHLO response from the server are in
violation of the standards.
practically speaking
a) most mailers these days are at least tolerant of 8bit content
in the message body
Most, but not all. Only a few weeks back I got a complaint about a message
rejection that turned out to be someone sending unnegotiated 8bit to a system
that was having none of it. Turning on conversion to quoted-printable solved
the problem.
b) most mailers these days advertise 8BITMIME anyway.
Absolutely true. Additionally, a lot of them downconvert when relaying to a
non-8BITMIME system, and some even upconvert when relaying to an 8BITMIME
system or when performing final delivery. I've seen cases recently where a
message was converted several times. And it has actually been a while since
I've seen a conversion that was done incorrectly.
Ned