Re: Antispam using *only* postfix/postcreen settings...
- On 01 Sep 2013, at 08:51 , Charles Marcus <CMarcus@...> wrote:
> Everyone else - I'm very curious how many people are relying solely on postfix/postcreen settings for their anti-spam measures, and how effective they seem to be as compared to other anti-spam measures - ie, using outsourced anti-spam SaaS providers (mxlogic, edgewave, etc).I still run spamassassin on mail that is accepted, but less and less is getting through.
I am considering moving spamd to a smtpd transaction phase filter since I think the combination of less spam getting in and more hardware to throw at the problem *may* make this viable.
My policy is that once mail is accepted, regardless of the score from SA, it is delivered to the user. Granted, it is delivered to the user's Spam folder and, really, they never look in there; also the folder is purged of messages over 7 days old automatically, but it's delivered. On most of my own accounts it is delivered to procmail which then discards almost all of it.
As an example, I have 83 spam messages in my main account since Tuesday morning. There were times I would have gladly sacrificed a limb for only 83 spam messages in almost a week (my main account doesn't trash the high scoring spam as do my other accounts). Maybe not *MY* limb, but someone's.
If I can *reject* spam messages that score... say, 8.0 or higher, that would eliminate more than 50% of the remaining spam. In the aforementioned account, 50 of the 83 messages scored 8.0 or higher, leaving only 33 that I need to look at. Of those 33, One (the lowest scoring at 5.0) looks like a weird NDN (double-bounce?), but I haven't had a chance to check the logs, so I'm not positive it is spam. Probably not.
The upshot is that plenty of spam still gets through. Postscreen is very effective, but just as rbls are not a panacea to spam, neither is Postscreen.
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