I'm needing to set up a remote mirror for a postfix server (where the content of both mail servers should be the same at any time).
The idea is that if the main server comes down at some point the mirror server will take its place, manage the new incoming mails, and when the e-mail server comes up again, it will update it with the new e-mails and return it the control to manage the new incoming mails.
The mail servers will be hosted in different places (i.e. maindomain.com, themirrorsite.com).
Getting a simple back-up server doesn't seem too difficult:
- http://beginlinux.com/blog/2010/03/backup-mx-with-postfix/
- http://www.postfix.org/STANDARD_CONFIGURATION_README.html#backup
- http://www.linuxmail.info/postfix-backup-mx/
But the problem is that this configuration wouldn't make the back-up site a complete mirror of the main mail server (it will hold only the e-mails received while the main server is down).
Is there a way to achieve the required configuration?