Help!!! Is there anyway Postfix can be configured to relay to a second/backup host in the event where the primary host is unavailable or down? I know that the 'relayhost' parameter only allows for single host relay, but I'm hoping there's a tweak or configuration change that can skirt that limitation. The use of external services e.g. BIND (DNS) and/or MX records is not an option in this case and neither is the use of a load-balancer. Therefore the configuration required has to be a function of Postfix itself. Please let me know if you have any thoughts or ideas that may help. Thank you.