On Wed, 5 May 2004 06:02, Keith Moore wrote:
the job of the submission agent is to authenticate the source (for
some meaning of "authenticate", to reject or fix invalid messages
(and provide feedback to the user that his MUA is broken) and submit
valid messages to the email transport system.
My earlier point still holds. Regardless of whether or not a client is
acting in the "submission" role or the "relay" role, it may or may not
be violating protocol somewhere in the transaction.
a relay is not violating protocol if it passes on the content it
receives intact, because the protocol should explicitly specify
that a relay works that way.
If a server performs strict protocol
checks at every stage of the dialogue, then it will reject such
violations; if it assumes that the client observes protocol correctly,
then it will propagate violations.
performing strict checking at every stage of the dialogue is a layering
violation - and it results in degraded interoperability due to server
implementation errors and variations in interpretation.
To put it another way, it's the client's job to pass on data only in a
way that observes protocol, but can the server assume the client is
doing its job?
if the protocol is defined to work that way, yes. and a sound protocol
architecture is one that has a clean separation of function, not one
where every component tries to second-guess every other component.
This seems to be largely a question of implementation.
nope, it's a question of design and architecture.
--
Regime change 2004 - better late than never.