On Tue, 11 May 2004, Daniel Quinlan wrote:
I concluded that yes, there sometimes may (and perhaps should) be a
significant delay between the receipt of an email and the SPF check.
1. message with indeterminate status (uncertain spam vs. ham,
SpamAssassin score of 4.5, or spam probability of 50%) is put into
purgatory and after some delay is tested again
2. SPF query fails for some reason, may want to test message (including
the SPF result) later
3. user installs anti-spam software and wants to check/filter messages
they've already received
4. any analysis of a spam, virus, etc. after it has been received
Of the above, I've done 1, 3, and 4.
Another example is if there is a significant delay before final delivery
and the spam checks don't happen until then. Reasons for the delay include
quota problems, or infrequently connected hosts, etc.
I note that since unknown modifiers are ignored, you can stick
valid-since=2004-05-11 in your SPF record now, if you want :-)
--
Tony Finch <dot(_at_)dotat(_dot_)at> http://dotat.at/