From: Lars Dybdahl
Sent: Monday, May 24, 2004 6:56 AM
That is before flag day, as I understand it. After flag day, if there
is no
RFROM/FRED/DAVE, we do an SPF check on MAIL FROM:. In other words,
after
flag day, a forwarded message with no RFROM will be rejected because
it will
not pass SPF.
In other words, the date of the flag day will be depending on the
forwarding services you use.
That is my understanding, too, for incoming mail. You can set your own flag
day for incoming mail when all your customers' forwarders provide the new
ESMTP DAVE parameter and prepend Resent-From: to the headers. Of course,
the very next day someone will set up a forwarder that is not compliant, so
only the last person to switch over will have no pain!
It's hard to imagine everyone doing anything by a certain date, so thinking
in terms of a transition period is more realistic. If Microsoft and AOL are
really behind it like we hear they are, hopefully the transition period
won't be too long. My guess is that if this is going to happen at all, the
largest players will determine the length of the transition period.
Whenever they start rejecting mail, everyone else will have to get in line
pretty quickly, at least for forwarding. Since they really can't do this
until stable patches are available for most of the common mailers, I doubt
anyone will be left out in the cold. How Microsoft will deal with older
versions of Exchange will be an interesting question.
On the other hand, there is nothing compelling anyone to do anything for
incoming mail and non-forwarded outgoing mail doesn't require any change.
--
Seth Goodman