The Spam and Open Relay Blocking System (SORBS) is a system used to help stop the spread of junk emails, also known as “spam.” This system works by blocking the websites and email servers that are used to send out these emails, so they can’t spread any further. It also blocks email servers that are referred to as “open relays” - these are servers that will send emails on behalf of anyone without verifying who they are. By blocking these servers, it makes it harder for spammers to send out their junk emails.