Oh come on, knock it off with arguing if Amazon is good or bad, none of that matters to me. My whole mail system is hosted on Amazon (2 MX and the Mail server) and as I said before, it has served me well these past 3 years. There have been a grand total of two internal IP address changes, one a surprise the other expected. Both handled within minutes with very little disruption in service as a result.
This is all academic because it doesn't answer the question of why the spam filter SPF suddenly spiked...
Can anyone shed some light on that?
(BTW Steve Reid, we are using Google public DNS.)