Depending on how your administrator has set up Enterprise Vault, you may be able to change the properties of archived items. In particular, you may have the option to change the retention category that Enterprise Vault assigns to the item. You may even be able to prevent Enterprise Vault from archiving individual items.
To set the Enterprise Vault properties of an item
In the properties dialog box, click the Enterprise Vault tab.
Do one or more of the following:
To suspend or enable archiving for the item, check or uncheck Do not archive this item.
To change the retention category that is assigned to the item, choose the required category in the Retention category list.
We recommend that you keep items with the same retention category in the same folder. Keeping them in the same folder lets you assign the retention category to the folder. The retention category then applies to all the items in the folder.
More Information
Setting the Enterprise Vault properties of a mailbox or folder