kraduk at googlemail.com
Wed Jun 23 17:59:56 UTC 2010
On 22 June 2010 20:36, Erik Norgaard <norgaard at locolomo.org> wrote:
> On 21/06/10 20.06, pete wright wrote:
>> On Jun 21, 2010, at 10:28 AM, Jean-Paul Natola wrote:
>>>> I'm particuclary trying to implement some type of rate control as we
>>>> are getting hammered by spam.
>> I'd humbly suggest pf + spamd if you are concerned specifically about
>> stopping spam, both are supported by freebsd and i have had great
>> success using these tools to combat spam.
> spamd does not stop spam. It is intented to increase the cost of sending
> spam at little cost to your server by keeping the spammer busy trying.
> If you're concerned with blocking spam from a limited set of known sources,
> then you can create block lists in your firewall. If you know that you will
> not receive legitimate mails from certain countries, you can block their
> assigned IP ranges.
> If you're trying to block large number of unknown sources, then I suggest
> subscribing to spamhaus' lists and configure your server to adhere strictly
> to the protocols.
> You may wish to subscribe to lists of dynamic ip-ranges. These are often
> considered spam sources hosting a large number of bot-nets However, you may
> also block mail from legitimate servers run by people who like to run their
> own home server - such as FreeBSD users.
> There is only limited benefit of some kind of rate control and I believe
> that such controls must be implemented in your mail server. Implementing
> rate control mail also delay legitimate mail, and depending on how you do
> it, spammers may even cause a DOS against your server.
> Anyway, to avoid spammers eating up server resources, check your server
> 1. ensure that the spam decision is reached as fast as possible
> 2. consider early whitelisting of the most common legitimate mail sources
> 3. DNS block lists should be last as they add additional delay, possibly
> you can configure a local dns cache to shorten delay
> BR, Erik
> Erik Nørgaard
> Ph: +34.666334818/+34.915211157 http://www.locolomo.org
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true spamd doesnt block spam it rates it. However these ratings on host can
be used to build an ip list which can be applied to a pf table.
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