Keeping a backup email server
I have looked and asked around but I've found no answer for this.
I have 2 mail servers (main,backup). Only main is visible from outside, backup is internal. All I want to do is have main receive and deliver the message to the local accounts, but also send the email to the backup server to be processed.
I don't want to use rsync, I want the backup server to process the email the same way main would.
Does anyone have any idea on how to do something like that?
Thanks in advance...
PS:Using 8.04/postfix/dovecot (debian testing version, ubuntu's doesn't have managesieve)