Arvel Hathcock wrote:
Hi Jim!
Yes, but suppose that the Sender header were used only when the domain
found therein matched one of those in the From. Then it would
disambiguate the process allowing SSP to know precisely which of the
multiple domains involved in authorship purports to be that which
posts the message to the mail stream.
This would not help in cases where the Sender: domain is entirely
different from any found in the From: but at least it would address
the root concern found in issue 1525. That is, it could no longer be
said that SSP requires the first author to be the poster (which is the
meat of issue 1525) and this issue could perhaps be closed?
But we have to handle the case where the Sender: domain is entirely
different as well. We can't just be silent on this case.
The choice of first From: domain is, as the draft notes, a largely
arbitrary one. I don't have a problem with using all of the domains in
the From: header field, other than whether we need to impose an
artificial limit on how many SSP lookups per message we do, and how to
handle the case where that is succeeded.
I do have a problem with just using Sender in the multiple From case.
Sender has different semantics than From, so using From under some
circumstances and Sender under other circumstances does "break" the
semantics defined in RFC 2822.
Cases in which there are multiple addresses in the From: and no
Sender: are inconsistent with standardized practice and the spec could
handle those just as it would messages that have no From: header at
all. I don't know.
I'm not worried about what we do with messages that violate 2822. But I
do want to make sure that we cover all the cases that are legal.
-Jim
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