Jon,
JK> The *use* of the data in SPF (for example) makes an assumption about the
JK> *source* (which is represented as an address which *can* be used for
JK> returns - this assumption supported by the RFC text). I gather that you
JK> hold that the RFC is wrong, that the assumption is therefore invalid and
JK> such use is incorrect.
yes.
It is a simple fact of the real world that a handling return address
is not in any way required to specify the author or sender of the
message.
JK> This is the point: I see the RFCs specify sender identification, which is a
JK> return address. Your position seems to be that all that's required in the
JK> real world is a return address, and that *use* of the data as sender
JK> identification is bad.
Not "all that is required", but "all that is actually done in the real
world today". I am not trying to assert a prescriptive necessity, but
rather am noting a long-standing empirical reality,
JK> Your problem is that if systems which use MAIL FROM as sender
JK> identification become widely deployed, the "real world" has changed out
JK> from under you. And you can't point at the RFCs to support your position.
My "problem" is the observation that proposals which require wide-scale
change to an existing semantic find themselves trying to overcome a
particularly massive barrier to adoption, and rarely overcome it.
d/
--
Dave Crocker <dcrocker-at-brandenburg-dot-com>
Brandenburg InternetWorking <www.brandenburg.com>
Sunnyvale, CA USA <tel:+1.408.246.8253>