Is it possible to have postfix set up to use an alternate outgoing server if an outgoing message fails for some reason? For example, if a user tries to send a message to an aol.com address, and the aol server replies that my servers ip address is blocked for some reason,can i set up postfix to resend the message through another server which will be configured as a relay? I usually monitor the mail queue and warning and error logs daily for any blocks, but it sometimes takes a couple of days for the providers at the receiving end to remove any blocks. I would like to set up an alternate path so that I can minimize any delays for my users. Thanks in advance for any ideas on this one.