On Wed, 2005-08-24 at 13:01 +0100, Nigel Metheringham wrote: > The problem is that SPF works fine if you look at it from the > perspective of an individual (with clue) - I know how my (legitimate) > mail gets to me, and can allow for that (so stuff thats being > legitimately forwarded via my vanity account with the federation of > yorkshire jelly wrestlers can be allowed for).
How do you know which machines the federation of yorkshire jelly wrestlers will be using for forwarding mail? It won't necessarily be the MX hosts for their domain, and it won't necessarily be the normal outgoing mail servers listed in their SPF record (even if they _have_ an SPF record). If you come up with some list of addresses which you think is accurate, what makes you think it'll still be accurate tomorrow? So no, even for the individual with their own private mail server it doesn't really work that well for rejecting false mail. And when you start trying to apply it to recipient domains with a large number of users, each of whom may have different forwarding arrangements, it's basically impossible. -- dwmw2 -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
