MailItem.Mileage Property (Outlook)
Returns or sets a String representing the mileage for an item. Read/write.
Syntax
expression .Mileage
expression A variable that represents a MailItem object.
Remarks
This is a free-form string field and can be used to store mileage information associated with the item (for example, 100 miles documented for an appointment, contact, or task) for purposes of reimbursement.