Hi there I wonder, if I can use ISPC as backup mx for another server also. Basically accept incoming email if the other server goes down and then forwarding it when the other server is back up again. Before ISPC I used this http://www.howtoforge.com/postfix_backup_mx It seems the Email_Routing and Relay_Recipients options can do it but I'm not sure if those are the correct settings since the backup mx howto says the relay_recipients = option has to be empty.
The backup_mx tutorias is not required for ispconfig 3 to enable a backup MX. In ISPConfig 3, you just add a mail routing (transport) for the domain to the master mailserver in the ispconfig mail module and then add the email domains or email addresses that shall be passed back after a failure undet Mail > Global Filters > Relay Recipients.
