I left the server to work off the load, as another server of mine seem to have had the same issue was re-booted and that sorted it. This is for sure and spam attack of some sort! it kills clamscan and spamassassin, eventually mysql process gets killed as the server run out of memory! and all get grinded to an halt!
I still have no idea how to get rid of this, were to find the "queue to scan as i stop both postfix and ispconfig_server, clamscan keep on spawning scans. Were is that backlog, how do i remove the heaped-up mail to be scaned! It also seem to scan the same mail over and over, as i got some mail 4-5x already. DARn!