Question : Policy for cleaning mailbox (Exchange)

Hi,
I am running an Exchange 2007 Server. I would like to delete items from all mailboxes on a daily basis so that items remain in mailbox only for 7 days. I would like to create a policy in the Exchange Server  to delete everything from the mailboxes except the "unread message."
I do not want to delete messages when they have not been read even if 7 days has passed. They should stay in the mailbox until they are read.
Could you please provide me with the steps to perform this task.

Regards,
Mark

Answer : Policy for cleaning mailbox (Exchange)

I don't think there is any way to do that with the mailbox management process, so you would be looking at a third party tool.