Re: [cobalt-security] Implementing spam Blacklists?

[Jaana Jarve <netcat@xxxxxxxxx>]

On Fri, 7 Nov 2003, Nathan Kondra wrote:

> Has any one implemented a spam blacklist?
>
> I am currently looking into implementing a dns based blacklist from
> spamcop.net?
> Has any one done it has it worked, has it reduced your spam.

yes, half the traffic nowadays being spam, blacklists are essential on
any larger mail servers. the PC term is blocklist, btw.

on topic of spamcop, we use it, but it's not the most conservative of
them. probability of false positives should be considered. it's also not
proactive, a host has to start spamming for real before it will get
reported to spamcop and listed. on the other hand it's one of the few
lists that an ordinary joe can submit to. (hence also the false
positives...)

i recommend using some lists that block known relays, proxies and dynamic
network ranges and are well-managed and have documented removal
procedures, first.

some examples:

dynablock.easynet.nl
proxies.blackholes.easynet.nl
list.dsbl.org

you can ask for advice, but don't take it blindly. in using any blocklist,
you're handing the decision of who can send you mail off to someone elses
hands. read every blocklist's homepage you are considering using. read all
documentation. decide for yourself if their policies suit you and if you
trust them.

rgds,
netcat