Do you have a dog inside that fence? Drivers are not going to risk a fenced dog.
My house is a long way from the street, so I built a parcel locker that is 20 feet from the road but not visible to passing cars. UPS, FedEx and USPS love it. Building a locker like that, just inside your fence, accessible without entering your yard, could solve this problem.
Since the United Parcel Service (UPS) does already offer the option to hold an individual's package for pickup at a UPS operating facility, if they determine too many delivered packages at your address are being reported as disappearing, UPS may suggest that permanent arrangement.
There are also a variety of parcel boxes which can be purchased and installed to hold your packages safe and secure.
http://www.homedepot.com/p/Gorilla-Box-P...
http://www.homedepot.com/p/Architectural...
http://busy-at-home.com/blog/the-elephan...
http://www.theibin.com/
http://www.steelmailbox.com/html/dvault.html
well you could get private mailbox at ups store that might work
You should ask UPS. They will know the answer.