When you need to access the fields in an item, the method you use depends on whether the field is a standard, built-in Microsoft Outlook field, or a custom field.
In either case, you do not access the field directly. Instead, you refer to the field as a property of the item you’ re working with.
For example, to retrieve the text from the Subject field of a mail message, you use the Subject property of the item, as shown in the following VBScript example.
mySubject = Item.Subject
If the field is a custom (user-defined) field, you access it using the UserProperties property of the item, as shown in the following VBScript example. This example assumes that the item already contains a custom field named ReferredBy.
MyReferral = Item.UserProperties("ReferredBy")