Your lucky day... I was just reading this on the amavisd-new page (http://www.ijs.si/software/amavisd/#features-spam): "... spam headers are inserted on a per-user basis according to their tag/tag2 level settings; this means that a multi-recipient message is split into clusters of recipients with same settings if needed (not available with milter interface). This permits per-recipient individual settings, while still being efficient for the mailing list traffic; SpamAssassin check is called only once per message regardless of the number of recipients, all header editing and actions taken is then done by amavisd-new for each recipient individually, based on its settings. "

-- Seth