Deleting Bayes Data and MySQL Tables

[Asai <as...@globalchangemusic.org>]

Greetings,

We've been running Spamassassin (3.3.1 currently, concurrently with 
Amavis) using MySQL as a backend for many years now and we have 1 
million + entries in the Bayes table.  At this time, there seems to be a 
lot of spam getting through the filters and we currently have our spam 
level set to 2.5 points for users with the most spam.

A couple questions:
Does 2.5 seem excessively low?
Is it advisable to clear out the Bayes table and start from scratch?
If so, would it be wise to raise the level to 4.0 while the Bayes data 
retrains?

Also, since we're using MySQL as a backend the sa cli commands don't 
seem to work as expected, for example sa-learn --clear doesn't clean out 
the MySQL database, nor does running sa-learn ... seem to produce any 
noticeable effect in spam filtering.  What am I missing?

Thanks for any insights.

-- 
--Asai

Re: Deleting Bayes Data and MySQL Tables

[John Hardin <jh...@impsec.org>]

On Wed, 9 Jul 2014, Asai wrote:

> Greetings,
>
> We've been running Spamassassin (3.3.1 currently, concurrently with Amavis) 
> using MySQL as a backend for many years now and we have 1 million + entries 
> in the Bayes table.  At this time, there seems to be a lot of spam getting 
> through the filters and we currently have our spam level set to 2.5 points 
> for users with the most spam.
>
> A couple questions:
> Does 2.5 seem excessively low?

Yes. The base rules are scored on the assumption that 5.0 is the spam 
threshold. Reducing the threshold will likely increase false positives.

> Is it advisable to clear out the Bayes table and start from scratch?

That depends. Are spams getting low Bayes scores? If so, that's an 
indication of mistraining and a need to retrain.

> If so, would it be wise to raise the level to 4.0 while the Bayes data 
> retrains?

If Bayes is generating FPs, yes.


-- 
  John Hardin KA7OHZ                    http://www.impsec.org/~jhardin/
  jhardin@impsec.org    FALaholic #11174     pgpk -a jhardin@impsec.org
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