Enterprise Vault for Microsoft Exchange - how to create system mailbox

Hi Everyone,

I am very new to EV. I want to archive mailboxes.

Currently I am going over prerequisites and see that system mailbox should be created in Exchange Server.

I have DAG space with 3 servers and 3 DBs.

I haven't previously worked with system mailboxes and now I don't understand how and in what amount should I create those system mailboxes.

Any guide, link, how-to is appreciated.

Thanks