ned(_dot_)freed(_at_)innosoft(_dot_)com wrote on 18.12.00 in
<01JXUFTWSWYK000046(_at_)mauve(_dot_)mrochek(_dot_)com>:
Now consider DSNs. Here the tradeoff is very different: Carrying the
information in the envelope has some costs associated with it, but the
benefit is that the resulting mechanism is reliable. A header-based
mechanism is inherently unreliable. The WG debated this and decided that
reliability was worth the cost. And while I'm sure that the purists were
pleased that this envelope information didn't get added to the header, I
don't recall this as being a deciding factor.
The problem, here, though is that the actual choice is very often between
an unreliable implementation (via header fields) and a useless
implementation (via envelope, which doesn't happen to be supported end-to-
end, and thus cannot work end-to-end).
And yes, I really do believe that the current definition is practically
worthless. Far too many MUAs and MTAs don't support it, and I see no signs
of this changing in the near future.
Now, a header solution is certainly less reliable, but I suspect it would
have the desired effect in significantly more situations.
MfG Kai