[qmailtoaster] Back UP MX

[Pribadi Kardono]

Hi all, I am using my qmailtoaster mostly as mailing list server. My question, is there anyway to have a back up mx that will continue to send/distribute the emails to the list whenever the main server down. Currently I have one primary mail server  and one backup mail server with setting mx on DNS are 10 for the backup. But seems the backup server never take over the primary to distribute the email while the main down. Is there anyway that I have to setup to make it works? Your help would be great full and appreciated.   Thanks   Pkardono