I know it's the week-end, but I just thought of this one...
We have backup tools in NE that backups everything "inside" Zimbra. But these tools, AFAIK, do not backup postfix' queues...
What I mean is that doing a full backup then a disaster recover will lead to lost mails, the one in the spools.
How do you NE admins backup (and restore) your postfix spools ?
The OSS community tools are supposed to backup the spools.
However, we're suppose to use a very special way to backup/restore them : Postfix Frequently Asked Questions