58. The apparatus of claim 57 , further comprising means for storing information from the two or more lists in an aggregate list data structure, and wherein the means for determining what lists indicate the message sender comprises means for querying the aggregate list data structure.
58. The apparatus of claim 57 , further comprising means for storing information from the two or more lists in an aggregate list data structure, and wherein the means for determining what lists indicate the message sender comprises means for querying the aggregate list data structure. 59. The apparatus of claim 58 , wherein a particular list is one of the two or more lists and the particular list contains one or more entries, and wherein the means for storing information from the two or more lists in the aggregate list data structure comprises: means for determining the difference of the particular list with a previous version of the particular list; means for storing entries of the particular list that were not in the previous version of the particular list in the aggregate list data structure; and means for removing from the aggregate list data structure entries that are not in the particular list but were in the previous version of the particular list.