There are several MAPI tools that you can use to look at the properties of items in Outlook, one of those is MFCMAPI. Here is how to use MFCMAPI to look at the Archived Date of an archived item in Outlook
Click OK on the dialog that opens up
Click on Session –> Logon and Display Store Table
Pick the profile, and click OK
You will see several different information stores, such as Public Folders, the mailbox and Virtual Vault (if you have that enabled). Double click on the mailbox to see the following :
Navigate through the structure to where the archived items are...