Keith Moore claims that there were SMTP servers in 1991 that _crashed_
when they saw 8-bit bodies.
Over the last few years I have repeatedly asked Moore for evidence to
back up this claim. He has never provided any such evidence.
This is my memory of what people were saying at the time. Various
problems were reported with 8bit bodies, and some of those reports
were of mailers that would stop functioning - refusing to process
other messages - when presented with 8bit input.
In 1997 I reviewed the old ietf-smtp archives and found a 1991 message
from Robert Ullmann on the same issue. Guess what? Contrary to Moore's
claims, nobody could find any SMTP servers that crashed on 8-bit bodies.
Face to face discussions aren't recorded in the archives.
Amazingly enough, the IETF _still_ doesn't admit that SMTP servers are,
as a practical matter, required to accept 8-bit messages.
This is probably an oversight which should be corrected. But at the
time that the SMTP 8BITMIME stuff was defined, there was nothing
resembling clear consensus that it was acceptable to just-send-8,
nor was there consensus that it was acceptable to require MTAs to
accept 8bit and downgrade (when necessary) to 7bit. And the discussion
on those topics was so long and heated (even without your help, Dan!)
that there was for many years a reluctance to revisit the issue.