Keith Moore writes:
No, but I fail to see how having an extra header (or not) would
affect that outcome.
MUA implementors are generally willing to change the interpretation of a
message _if_ a new header field is supplied.
This doesn't affect current users. The important question is whether the
likely future benefits outweigh the implementation and deployment costs.
Without the header field it's more difficult to evaluate the current
costs. In some cases such a change would impose huge extra costs on
current users; if you ask implementors to do that then you lose.
Again, I'm not saying that the extra costs of what you're proposing are
obviously larger than the benefits. But it _is_ obvious how the costs
_could_ drastically slow down the transition. More study is required.
We will almost certainly need a UTF8 SMTP option anyway,
Why? Explain the benefits and costs. Remember that the argument for MTA
Q-P conversion failed in the real world because it wildly understated
the costs of Q-P support.
the vast majority of deployed MTAs cannot handle 8bit headers,
Data points: qmail is 8-bit-clean. sendmail (8.8.0 and above) removes
bytes 128-159. The Cyrus IMAP toaster, apparently, bounces any message
with an 8-bit header field. Any other reports?