text_combined: aio shin qysavczgmailcom maybe load balancing part right yet tried suspect amavis created bottle neck temporarily disable amavis postfix working filtering rbl listing queue cleared fast tried increasing max server amavis 2 15 also increase amavis smtp unix process masterconf 15 resolves long queue hold time side effect cpu usage increase amavis works maximum solution relay email postfix servers addition reduce load let relay domains bypass spam virus scanning thanks sharing advice thu 07 aug 2008 231605 0800 attaining 20 sent mails per second