ned+ietf-822(_at_)mrochek(_dot_)com <ned+ietf-822(_at_)mrochek(_dot_)com> wrote:
And it isn't a binary choice between rejection and fixup either. What sort of
fixup makes sense can change over time.
The draft suggests an intermediate option, which is to process the message
using a grammar with more lenient handling of error cases but to pass on
the message unchanged (if it gets passed on). A lot of the risk comes
from doing this (or rather, from doing this inconsistently). I think I'd
like to make a distinction between a relay (which is transparent) and a
security gateway (which does fixups). They should have consistent
behaviour, by which I mean that if a transparent relay is presented with a
corrupt message, it should treat it in the same way as a standard parser
would treat the same message after it has been fixed up by a security
gateway.
Whether a message gets rejected or not is a somewhat different matter. I
think submission servers can and should be a lot stricter than an MX can
be. Either way, every system needs to parse borderline cases more
consistently.
Tony.
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