[SURBL-Discuss] SURBL DoS possible?

[Markus Zingg]

>What would happen if a spammer intentionally starts putting hundreds
>of different invisible random URIs within the message trying to DoS
>SURBL?

I can't speak for the plugins you mention, but in my implementation I
look exclusively for visible URIs and ignore all others. Then, having
such a high number of URIs would definately be an excellent criteria
to flag the message as spam just because of this.

IMHO blocking on spamvertised URIs is the most effective aproach to
the problem. There is really no way out - not even your scenario
provided the server is propperly implemented. We have a local database
of spamvertised domains on our server and therefore the performance
drawback would not really matter that much. This database is then
updated every now and then which obviousely generates less traffic.

Markus