[Dovecot] Live Mirror dovecot / OS X 10.6.4

[Eric Boltz (MMI/UPC)]

I want to set up mirrored postfix/dovecot servers using two mac mini servers (OSX 10.6.4)  located in different locations (Canada and the US to be specific) for redundancy.
The idea is to have one as the primary MX ("mail.corp.com") and the other as the secondary ("webmail.corp.com"). If the primary goes down clients would revert to webmail until the primary is back up.

The plan is to use rsync for this. My challenge, however, is what all I need to rsync to have a "live" backup. Rsync for backup isn't an issue, but I will need to rsync users (system and virtual).

Anyone have experience with this? So far it seems that apple puts things in lots of non-standard locations. I suppose I could to a blanket rsync on /var, but that seems a bit much.

Thanks in advance.