Converting SuSE to use MailDir instead of MBOX

Hello is there a howto out there or some sort of instructions or tips that you could provide that could explain how to convert the default settings of the suse 9.1 and 9.2 systems to use MailDir instead of MBOX. i need to setup my system for multiple domains and include anti-spam/virus features but they appearently require the usage of MailDir instead of MBox. All handed help is greatly appreaciated Season Greetings Matice