[CentOS] spam control

[James Fidell]

R Lists06 wrote:
>>>> I have added the following to /etc/mail/sendmail.mc and rebuilt it
>>>> trying to control spam. I still get about 25 spam messages a day.
>>>> Is there something else that can help control spam?
>> I recommend greylisting.  Check out <http://www.greylisting.org>.  I run
>> gld with a postfix MTA.
>>
>> Barry
> 
> What RBL's, if any, do you use if we may ask?

I have found that greylisting based on the Spamhaus sbl-xbl list
massively reduces spam.  Setting that up on my backup MX
resulted in all traffic through it stopping when my primary MX is
up.

It's sorely tempting to set up a lowest-priority MX that either
points to 127.0.0.1, or to a machine that has a daemon on port 25
just returning 4xx SMTP errors in response to every connection.

James