At 16:56 23-10-2008, Luis Croker wrote:
> I have a mail server with FreeBSD 7.0,
> postfix+amavis-new+spamassassin. We are an ISP and I need to
> filter the spam that our susbribers are sending to internet, the
> PCs have some malware or are botnets. These PCs generates a lot of
> spam each day.
> The server filters a los of Spam but some times the queue is so
> crowded. I have to questions...
>Do you have any recomendation to improve the performance on the server ??

>How can I catch more spam than the seerver is filtering ? The server
>blocks many messages but another spam messages goes to internet
>cause the score does not reach the parameters to be blocked.

If you are running an old version of SpamAssassin, update it. Run
sa-update to keep the rules updated.

Analyze SMTP traffic to detect any signs of abuse and quarantine
these hosts. You may have to reach out to the customers and help
them clean infected hosts. Use the feedback from your abuse
department. You can also get feedback from anti-abuse groups and
subscribe to feedback loops. Identify the spam messages not reaching
the threshold and add rules to catch them.