http://www.cyberciti.biz/faq Every answer asks a more beautiful question. Fri, 03 Feb 2012 22:38:32 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 http://www.cyberciti.biz/faq/postfix-backup-mx-server-anti-spam/ http://www.cyberciti.biz/faq/postfix-backup-mx-server-anti-spam/#comments Tue, 28 Apr 2009 21:40:47 +0000 Vivek Gite http://www.cyberciti.biz/faq/?p=3694 According to RFC2821 the lowest-numbered records are the most preferred MX for domain. So I've a target Postfix backup server to keep the messages in a queue waiting for the primary server to become available. This ensures that if my primary MX goes down I do not loss any emails. However, spammers are connecting to my backup MX to avoid anti spam filters that are running on the primary MX server. This also hides their real IP from my primary MX. How do I configure anti-spam for my backup RHEL / CentOS 5.3 based Postfix mx server?]]> http://www.cyberciti.biz/faq/postfix-backup-mx-server-anti-spam/feed/ 13