UCEProtect is a IP blocklist that mail server owners can use to block certain IP addresses from delivering emails to their users. It is a system that is a useful spam indicator, in conjunction with content analysis, link analysis and other tools. However, UCEProtect have a massive failing - they tend to block IP address ranges (rather than a single IP address). This will help with the spammer that use changing IP addresses, but also will block countless other users. At the moment, they have blocked an entire range of BT email server... read full review »