ArchiveOne is licensed by the number of mailboxes allowed to be processed. The license grants one ArchiveOne Service installation the right to connect to a named Configuration server, then process as many mailboxes on the Exchange site or admin group as is allowed by the license.
If you want multiple ArchiveOne Service installations, each must connect to a different Configuration server, and be separately licensed. This allows each installation to process as many mailboxes as required or specified by the license.