[Dovecot] Unoffical Survey - What MTA/Spam filtering do you use?

[Simon Waters]

On Wednesday 19 Apr 2006 10:45, Reuben Farrelly wrote:
> 
> I'd say with a lot of confidence that I've had more false positives from
> dynamic blocklists tagging email than HELO checking (perhaps not
> surprising).

The spamhaus list is amazingly good -- and also provides genuine senders with 
an automatic way out.

But as regards HELO, I know what the rules for HELO state, and so I know why 
it should work (even if it is considered RFC infringing). But I've never seen 
a detailed analysis of HELO strings in the same manner as I've seen studies 
for the effectiveness of different RBL.

What I want to see is someone saying "X% of our normal genuine email servers 
were (would have been) caught" & "it stopped (or would have stopped) Y% of 
spam". 

Lots of anecdotes don't cut it I'm afraid, not that I don't believe the 
people, just it is different when it is someone elses email you are 
filtering, especially if you are making a Yes/No decision on accepting email 
on the basis of the test. I need to know if it is <1%, <0.1%, or <0.001% 
false positives, as that'll establish how many people get angry. Obviously 
email sources vary, but I need to know where to concentrate the effort.