I will try to explain the issue. Sorry if this been covered.
We are using Exchange 2010 Sp2 RU4v2
We created a new Rention Policy with
all other folders older than 90 days move to archive
Disabled conversation history
Disabled Junk Emails
But when it run's it's taken both these other folders and archiving them as well.
Only work around we have to date is to use a RPT against inbox only which works but doesn't then archive automatically any folders that have been created at the root level of the mailbox