Hi! Are there other solutions around spam-filtering on Linux/Postfix with ISPConfig? I still get a lot of spam... gray-listing is on too Thanks!
RBL are blacklists that can be integrated into postfix, e.g. http://www.spamhaus.org/ http://www.faqforge.com/linux/enhanced-e-mail-spam-protection-in-ispconfig-3/
System -> server config -> choose server -> tab "mail" -> field "realtime blackhole list" -> zen.spamhaus.org -> save.