I have a shipping/post office box shop (for 26 years). First, anything over 13 oz. is called priority - not special. Second, there is no such thing as 2 day mail. Ask the post office when you send it 'priority' and they will tell you they will attempt to deliver in 2 days. There is no guarantee and it can take from 2 days to 2 weeks. If you must send it USPS, please add something - delivery confirmation, return receipt, insurance, something to give you additional tracking info. I only send things UPS ground or FedEx ground. If you do it online or go to a smaller independent shop, it is fairly close to the USPS price for several pounds and you get a tracking number, $100 insurance and a date certain for delivery. This helps for you to notify the person on other end as to the exact date for delivery. I always lay a plastic bag on the bottom of the box to prevent moisture sucking thru and put a note with the to and from address inside the box. Reminder, you do not need to use a new box, reuse one you have as long as the label is visible on top. My customers bring me all their boxes and peanuts so that I can recycle them for customers and not have to charge for them - helps out everyone. If something does happen, UPS and FedEx are wonderful with their claim process, USPS can take months if they do honor the claim. Sorry if this sounds like bashing, I know the USPS does deliver a tremendous amount of mail, it is just when there is a problem, they can be very difficult.