From: John Stanley (stanley@peak.org)
Date: Tue Oct 31 2000 - 13:22:32 CST
Charles Lindsey (chl@clw.cs.man.ac.uk) says:
> Yes, but since our draft does not define any specific "operability" for
> this header (otherwise than to be informational) we could hardly say that
> any interoperability would be lost if it wasn't there.
This statement applies just as well to the From: header. The spec says it
contains the email address for the sender (as if there were just one email
address for most people anymore) in internet format. It doesn't say "you
can get mail delivered to that address.", and even if it did, it would be
crossing a boundary into specifying mail behaviour in a news standard.
> But this case IS different. The "operability" of the From header is well
> defined (it is for generating email replies, amongst other things).
I don't see that in the definition of the From: header, and like I said,
even if it was there, it's defining mail actions in a news standard. I
thought we couldn't do that, according to what people say here.
> And
> munging it has visible evil effects on the network (like causing extra
> unnecessary DNS lookups).
First of all, "lookups" are not visible to anyone not running a
network monitor when it happens, so "visible" is a specious claim. Second,
there is not a news server running that does DNS lookups on the From:
header. They don't cause any, so they can't cause "extra". If they don't
cause any, then they can't have "visible evil effects" based on DNS
lookups.
It's only when a few people decide they must send mail that any DNS
lookups are done, and the load is usually less (for an immediately
rejected invalid host name like "aol.com.nospam"). In this case, I will
agree there are unnecessary lookups, but that's not because the address is
munged, it is because people think they have to send email. If they don't
want to eat the cost of the DNS lookups, then how in God's name can they
pay for actually sending an email to someone?
This is one time that those who call From: an interoperability issue to
bite the bullet. Either admit that it is just a convenience, or admit that
these headers are interoperability too, because every argument that
applies to From: being interoperability applies to these headers, too.