FROM address: This is the default address that appears on the SHIP FROM part of the label. It defaults as your company address but can be changed to another address. The rate will always be calculated using this FROM address.
RETURN address (OPTIONAL): This address is optional and should only be used if you need to show another address on the label that is NOT the pickup (FROM) address--i.e. BLIND SHIPPING or the broker's address.
For example, let's say your business is located in Texas (the pickup address) and you are shipping to a destination in New York. However, you are blind shipping on behalf of a broker in California.
If you want the label to show ship from California, shipping to New York, and pickup in Texas, you would setup the shipment as follows:
FROM: Texas
TO: New York
RETURN: California