howard chen wrote:
Hello,
I am new to SA, I have read through some of the faq and wiki, so far
can't find the average spam rate % detected by SA. I know it is not
the same for everyone, but I want to get the feel of general
statistics (If you don't mind to share)
1. How many Spam detection rate if I am using default 3.2
configuration you would expect?
Depends on your settings, ie: are you using bayes/network tests or not.
However, anywhere from 92% to 98% of spam should be detected out of the box.
See also: STATISTICS-set*.txt in the rules directory of the tarball for
your release.
2. If fine tuned according to the wiki, e.g. running sa-update, more
rules set, how many % you would expect then?
Well, depends on how you tune. You can easily make SA have 100%
detection rate for spam, but your false-positive (FP) rate will also be
100% :)
That said, a well tuned, well trained, well maintained SA should be able
to detect 99% of spam with a less than 0.1% FP rate.
3. Is the % vary from SA version? e.g. 3.0, 3.1 and 3.2?
Certainly. Using an older release of SA against recent spam will result
in significantly lower detection rates. The code really does matter
quite a lot to detection rate. Things like tweaks to the HTML parser
that deal with spammer obfuscations and improve accuracy are made in the
code, not the rules. If you're using an older SA, you're missing out on
these tweaks.
Also, generally speaking, sa-updates aren't made for older release
families. There's usually a period of overlap when a new family comes
out where both the current and previous versions get updates pushed, but
that generally comes to a stop once development shifts full-bore to the
next release.
At this point anyone using 3.1.x is stuck with rules from October 2007.
The 3.2.x rules (at the time of this writing) were last updated in June
16, 2008.
Thanks...
