There is a great danger in setting up to honor the good, art the
expense of the best in certain very interesting cases. As always, one
cannot apply such sikple rules as "Avoid the best in the interests of
the good!"
Take for Special Delivery as it once existed in the US Postal Service.
It turns out that suddenly on e year (about 1975) the USPS would no
longer leave a special Delivery envelope at a residence if there was no
one there to personally take possession of it.
Special Delivery had signature required" rule, and no accounting for
receipt, but suddenly, if I was not home to receive it, the envelope was
taken back to the post office and I was left a notice to go there to
pick it up. Worse yet, since it was Special Delivery, it was not my
local office, but one much farther away, because they used special post
office stations to handle all Special Delivery mail.
When I enquired about s degradation in service, I was told that the
problem was with many illegal aliens using special delivery in place of
registered mail, so they were now treating Special Delivery as though it
was Registered Mail, and would no longer leave it in a residential
mailbox.
The problem is that quality of certainty of delivery went up, but the
variance on time of delivery went to hell. The USPS apparently was not
aware that the special value of Special Delivery was "FAST DELIVERY".
Special Delivery service was thus destroyed, and it is now useless, and
not used.
By analogy, it is my position that if we allow any random MTA to decide
to "downgrade" the quality of the content of a message without explicit
permission from the SENDER's or the RECIPIENT~s UA Authority, then we
have created a monster and will destroy the value of sending anything of
value via netmail, precisely because we will not guarantee anything
about the possibility of conversion and potential destruction of the
value of the content.
In short, it is not better to get a FICHE of the Dead Sea Scrolls (with
the originals destroyed) if you posted them with the expectation that
they would either be delivered as posted, or returned as posted, without
destruction.
It is not always better to get something more than nothing!!!!
We are dangerously close to changing mail to be unreliable by design,
like an ETHERNET. It is fine for an ETHERNET where we all understand
that the design calls for loss of stuff, so we all deal with it in those
terms. But, we do cannot design Netmail to have this property of loss.
Cheers...\Stef