Exchange 2007 Backup/Recovery Advice

Exchange 2007

OK, so I find myself with 40 mailboxes that have NEVER been backed up, and an admin has set Managed Content Policy that has perm. deleted everything in their mailboxes, including contacts, etc. older that 14 days.

The only hope I have of getting these back is a years worth of transactions logs – 70GB.

What can I do to restore the mailboxes, including contacts to a state from one week ago….

Can this be done

Thanks in advance for any advice.