US Patent 7945674 Degrees of separation for handling communications

A sender's degrees of separation from a recipient may be used to aid in spam filtering or to otherwise handle a communication. The “degrees of separation” represent a metric used to quantify whether/how the recipient is linked to the sender through intermediary people or other entities. A level of “trust” or “legitimacy” about a sender's communication can be inferred by looking at whether the sender is linked to an intended recipient. Typically, user contact lists (e.g., address book, buddy list, and/or white list) are evaluated to determine the number of degrees (or hops) are required to link or relate two users.