aio shin qysavczgmailcom sorry giving complete scenario mx relaying 3 mail servers 3 mail server 1 also postfix others exchange yes also serves spam virus scanner via amavis mentioned 1 domain thus postfixamavis set bypass scanning mx host scan intended remaining domain uses ms exchange ables flush queue fast set 30 amavis processes since amavis amavis defaulted 2 max_server 4 smtp process current cpu age right think settings used since amavis started correct wrong fri feb 22 2008 1258 pm ram wrote role server antispam box sitting mx asking lists help give complete relevant scenario thanks ram fri 20080222 0323 0800 aio shin wrote 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 fri 08 aug 2008 032822 0800 attaining 20 sent mails per second