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Matt Kettler mkettler at EVI-INC.COM
Wed Jul 13 19:57:57 IST 2005

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David H. wrote:

> Actually you should first look into the Custom Ruleset. While SPF is a nice
> thought it does not work at all. I have seen enough messages that have been
> marked as valid Spam and had a SPF_PASS header in them.

Er, so what?

SPF can pass for spam, that's perfectly normal. It's even expected. That's why
SPF_PASS only has a -0.001 point score.

SPF IS NOT a spam detection technology. If anyone else tells you different
they're full of *explicative*.

SPF is a forgery detection technology. Period. Do not expect it to pass for all
nonspam and fail for all spam. That's not what SPF is for, or what it does, or
what it could possibly ever become based on it's specs.

While SPF isn't a reliable spam detection technology, it is a good forgery
detector. And the fact that a message is forged is a good sign something is wrong.

Thus SPF failure is useful in spam filter, while spf passing is merely
informative about the source, but doesn't tell you anything about it's spamminess.

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