Master/Slave functionality?

[Del]

Thanks for your help Alain, it is highly appreciated. I am afraid I have
many more questions...

> - Slaves and master are all identical except the ldap is running on
> the master. I dont thing if some ldap replication are done between
> slaves and master.

So what exactly happens if the master node goes down? Will no users be
able to access their accounts from a slave? How about incoming mail,
will a slave with an mx record pointing to it be able to receive
incoming mail if the master is down?

What about if a slave hosting an account is down, will another node
receiving the mail accept it on behalf of the hosting node? If so, will
it be redirected once the hosting node is up and running again?

> - You have to choose which node will host any new mailboxes you will create.
> - Any node can receive email for any mailbox and redirect it to the
> "hosting" node
> - Users have to use the good node to connect using imap or pop3, I
> thing Horde is able to redirect query to the good node.

What does good node mean? Do you mean any node that is up and running,
contrary to the hosting node being down? If so, I assume that it does 
not apply to the master node being down (due to lack of user authentication)?

Cheers,
Del