[CLUE-Tech] Stopping freakin' spam on the mailman lists

[David Anselmi]

charlie oriez wrote:
 >
> Another option you have is to refuse mail from any site where rdns is not 
> properly configured.  Most spam these days comes through open relays or open 
> proxies.  Once the spam hits and gets reported, the open relay or open proxy 
> gets onto the appropriate dnsbl in the osirusoft suite and gets blocked by 
> users.  The interesting thing is that most administrators who leave security 
> holes open on their system also can't figure out how to get rdns configured 
> correctly, so refusing traffic from systems without rdns configured seems to 
> stop additional spam from new sources even before it gets reported to the 
> blacklist maintainers.  You can probably get implementation directions from 
> the anti-spam fanatics :-) on news.admin.net-abuse.email

How do you define a properly configured rdns?  I ask because I run a 
server who's IP doesn't reverse lookup to my domain.  My domains have 
dns entries on several different name services, but my IP block is 
delegated to my ISP.  So they have the reverse lookup zone.

I haven't asked them to put in a "correct" pointer because it seems like 
a lot of trouble for one lousy IP (and I don't want to advertise that 
I'm not running a domain through them).  Call me cheap but at the moment 
  the project doesn't warrant more resources than that.

Any thoughts?  I don't currently run much mail through here but I might 
like to so I worry that my server will get rejected (it did at some 
places before it had a forward dns entry).  Perhaps using my ISP's mail 
server on the way out would help?

Thanks.

Dave