Exchange Server 2007 has the tools to help you achieve email-retention compliance both with current legislation and your company's particular needs. These steps outline the procedure to limit Inbox items to three-month retention while holding all messages related to a specific account for five years.
Step 1: Create a Folder with a 5-Year Retention Period
Use Exchange Management Console to launch the New Managed Custom Folder wizard. Create the managed custom folder for your specific account, then use the New Managed Content Settings wizard to configure a five-year retention policy for the folder.
Step 2: Set a Mailbox Retention Policy
Use the New Managed Content Settings wizard to set a three-month retention policy for user mailboxes.
Step 3: Create a Managed-Folder Mailbox Policy
Use the New Managed Folder Mailbox Policy wizard to reference the retention period for the Inbox. Repeat this step to create a second managed-folder mailbox policy and associate it with the managed custom folder.
Step 4: Associate the Policy with Mailboxes
Associate the retention policy with a particular mailbox through the mailbox properties sheet's Mailbox Settings tab.
Step 5: Create a Transport Rule
Create a repository mailbox for messages relating to your specific account, then use the New Transport Rule wizard to create a rule that moves messages relating to the specific account into the repository mailbox.
Step 6: Move Necessary Items to the Managed Folder
Use an Outlook rule to move items relating to the specific account from the repository mailbox's Inbox to the managed folder with the five-year retention policy.