I'm creating limit-templates for resellers and clients and so I'm wondering if there is a way to create a combined qouta so the reseller has 20 GB and he can distribute/use how he wants between web and mailbox?
This is possible as described in the manual, see setting System > Server config mail tab. But this is really bad for security as it requires the mailboxes to be owned by the web user so they fall under his quota. The result will be that a hacker of a website will be able to access all your mails. So I would never do that on any of my servers.
Didn't find that in the manual. So if I wanted to do that I need to change the user the mailboxes are owned with the client? It's a multiserver setup so the web and mail servers are standalone.
Then this won't work anyway. A shared Mail and user Linux filesystem quota requires that mail and web data is on the same server and on the same physical harddisk partition.
