On 10 Oct 2004, John R Levine wrote:
Right now no MTA handles MASS mail signatures, so transition model is all
the same for any proposal and involves adding new programming. ...
Your MTA handles MASS. My MTA does not handle MASS. You send me a
message. What happens? That's the transition question.
That depends on how final MASS system would look like. But I would expect
that nothing special happens - my MTA sends message with signature embedded
as MIME object, your MTA ignores the signature and passes message to your
MUA. Your MUA ignores the unknown MIME part and displayes normal mime text
parts to you.
Some MTA (early adaptors) begin to add signatures. At first most don't
know what it is and they are simply ignored by MTAs and by MUAs.
As has been pointed out about a dozen times in the past week, quite a lot
of mail is received by programs that are not MUAs. They include mailing
list managers, service gateways, and other stuff. A lot of those programs
don't handle MIME at all. If MASS adds MIME sections to mail that used to
be plain text, a lot of those programs will fall over and die when they
get MASS-ized messages.
They already handle MIME. Its question what kind of MIME they can handle.
All mail list managers I know will look in the email body for first line
that says "subscribe" (or unsubscribe or other command), sometimes if its
text-only message this would be first line in the body but if message is
mime encapsulated (or if it has PGP signature), the line would be somewhere
down in the email body and on top of it would be MIME encapsulation lines.
And this is not a problem for most mail list managers, they still can work
with such emails.
As far as service gateways, I don't know enough about how they are setup,
but I think it is an extremely rare case if email gateway simply can't
handle MIME messages at all. As I said before - 99.99% of emails are now MIME.
The only conclusion I can draw from your mail to date is that you expect
that MASS users who wish to communicate with non-MIME applications are out
of luck unless and until those applications are rewritten to add MIME
handling.
I'm willing to allow for special cases where user can indicate that this
mail is going to special gateway and should not be MIME encapsulated. The
easiest way is for MTA to check if email contains "Mime-Version:" header.
If this header is not present then MTA should assume that email is meant
to go to non-mime capable gateway and should not add MASS signature.
If that's your intention, OK, although that strikes me as kind
of a lot of collateral damage. If that's not your intention, you'll have
to explain more clearly how the mail will continue to work.
I think I explained it, see above.
---
William Leibzon, Elan Networks:
mailto: william(_at_)elan(_dot_)net
Anti-Spam and Email Security Research Worksite:
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