Where does Mi5 get the databases for the Webgate appliance?

Mi5 combines leading third-party anti-spyware, anti-virus and URL filtering libraries, with its own research and detection algorithms.

Does the Mi5 Webgate appliance support Whitelisting and Blacklisting URLs or IP Addresses?

Yes, the Mi5 Webgate appliance supports the entry of URLs and or IP Addresses into its Whitelist, to allow access to a site, and Blacklist to block access to a site.  Host or subnets put in Whitelist are not analyzed.