Re: [exim] Exim and SPF

Marc wrote:
> Sometime flawed technologies still have uses. SPF breaks email
> forwarding. But using that flaw I may be able to detect forwarding
> sources through SPF failures. The idea being that if it's legitimate
> email but SPF is wrong then the message was likely forwarded from a
> legitimate source.

True that even if a technology isn't perfect it can still have its uses,
however...

If you are going to use SPF to try and figure out who is potentially
forwarding email via failed SPF, how would you differentiate between a legit
forward and a faked spam message? You'd have to implement a list; in the
end, you'd end up implementing SPF as it was intended (while avoiding its
flaws), yet you would likely not want its results because you consider it
useless for its actual intended purpose?

Eli.