SORBS, a public service, or just a scam.

rootnl writes: Recently I decided to upgrade my email server with better spam detection and decided to use SORBS dnsbl.sorbs.net blacklist. It is a very aggressive blacklist and could be deemed quite effective. However I discovered two totally legal servers beeing blocked by their Spam 'o Matic service. One a Google Gmail server, nf-out-0910.google.com[64.233.182.185] and the other a ISP called Orange, smtp-4.orange.nl[193.252.22.249]. Now normally one would think these providers would probably get themselves de-listed, but the process provided revolves around donating money. As I just happen to have a friend that is using the said ISP, I have to seriously reconsider using SORBS. What is your experience with SORBS? What will happen if somebody start to sabotage Gmail or any other mail service by forwarding spam to one of SORBS spamtrap servers? What would you suggest as better blacklist service?