advice on anti-spam tools

[Martin Hudec]

Angelin Lalev wrote:
> My e-mail server is running the latest spamassassin with all of the blacklist enabled and etc. 
> but I still receive over 20 spam messages a day ("image" spam mostly). 
> The situation with other users may be worse.  That's why I was thinking about some tool that 
> 1. store incoming email
> 2. send request to the sender of the message, requiring to go to some address and enter the numbers (letters) 
> from image
> 3. if the puzzle is solved in time (week or so) deliver the message, otherwise delete it.
> 
> Is there such tool(s) ?

As for image spam, it might be worthy to try out that mail/p5-FuzzyOcr 
as recommended by Kurt few days ago. I am considering to deploy it, as 
majority of the spam I am receiving is image one. Also check 
mail/spamass-rules_du_jour.

 From my experience, simple setup of spamassassin, also feeding it with 
samples of 3800 spams and 3000 hams, and deployment of these rules du 
jour allowed me to get from (counted on per day basis) 314 spams to 8 
spams received to all of my 12 domains I have on my system, actually 
with two of those domains having some of their mail addresses spreaded 
widely on the net on various maillists etc. Data are statistical from 
January measurements, and though they might not be that much impressive 
in larger scale, they serve my purposes very well (getting to ~2.5% of 
the previous volume is quite fine for me). And one more thing, I do not 
have any greylisting at all, which would probably help the things even more.

nice evening,
Martin