Overview
A SORBS database listing will have minimal influence on ISP blocking decisions.
How it works
SORBS uses several methods to identify potential spammers. Most of their lists use spam traps to identify problematic senders. But SORBS will also list a sender based on their own user complaints, if SORBS administrators have received spam from the sender, or if they identify other high-level sending behavior patterns characteristic of spammers.
Remediation
There is support for manual requests to remove or delist your IP Address from the SORBS database. More information about delisting can be found at their website: http://www.sorbs.net/lookup.shtml