- How to stop spammers bringing our server down?
- Posted by Greg Hennessy on November 3rd, 2007
On Sat, 03 Nov 2007 11:00:39 +0000, Peter
<occassionally-confused@nospam.co.uk> wrote:
assuming a recent version of FreeBSD.
Implement empty ACK Prioritisation on the 448 k reverse path.
Use Dummynet or ALTQ to shape email traffic.
Use PF to rate limit inbound port 25 traffic.
Implement Greylisting.
Use PF's Spamd to catch and tarpit spammers.
greg
--
?ˇaah, los gringos otra vez!?
- Posted by dennis@home on November 3rd, 2007
"Peter" <occassionally-confused@nospam.co.uk> wrote in message
news:g8cpi3ttdmrlct3lvsp7hdusffnh9d55d5@4ax.com...
As your troubles started when you went to 8M down I suspect your server just
can't respond to all the incoming stuff over the 400k uplink.
You could try throttling the downlink to see what happens, say 1M/2M.
If this works and is OK then all's well.
If it works and you need more bandwidth you have a few choices..
rent a server and move all your mail handling to that so it has plenty of
bandwidth to cope.
get a second link for other stuff and leave the mail throttled.
move to a provider with a bigger uplink (who doesn't mind 10k+ messages a
day).
- Posted by Dave Wade on November 3rd, 2007
"Peter" <occassionally-confused@nospam.co.uk> wrote in message
news:g8cpi3ttdmrlct3lvsp7hdusffnh9d55d5@4ax.com...
No , basically greylisting relies on two facts:-
1. Most spammers don't bother to retry failed connections.
2. They keep changing IP address.
So on the first connection you receive from a particular IP you drop the
connection with a re-try later. Because the spammers are using hi-jacked
machine manging re-tries is costly and they don't bother. See:-
http://greylisting.org/
for more details...
