On Wed, 2008-06-04 at 18:24 +0200, Benny Pedersen wrote: > On Wed, June 4, 2008 17:11, mouss wrote: > > > If they can't configure their system to reject invalid recipients at > > smtp time, there is no hope that they will setup SPF checking correctly! > > it was olso my conclusion after i have writed it :-) >
You might be surprised , but that is not exactly true. I have seen a lot of backscatter from Cisco Ironports. Most Ironport boxes dont do any address verification at the time accepting mail, and then send NDR's. But if these are getting SPF fail, then these messaged may get discarded as spam ( I assume ) And this may happen with a lot of other outsourced antispam vendors too