> At 10:50 10/09/97 +0200, you wrote:
> >At present our algorithm(s) look something like:
> >
> >* accept SMTP connection
> >* get address of remote
> >* is it in a list of blocked servers? If so, don't allow mail
> >* else start SMTP dialogue
>
> Do you run _all_ the MX servers for your domain, or do you have any ISP
> back-ups? I think your scheme will only work if you run all the servers
> and hence can put these filters on all server for your domain. Anyone with
> ISP relays, will find that the primary server rejects the spam, and the
> spamming relay tries the ISP relays instead. The ISP relays accept it and
> then the primary server accepts it from the ISP relay.
Our ISP is running one of our firewalls as well...
--
Dr Graham Wheeler E-mail: gram @
cdsec .
com
Citadel Data Security Phone: +27(21)23-6065/6/7
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