Yes, MyUS can ship to P.O. boxes via the following carriers to these countries: 

DHL Express:  Afghanistan, Albania, Algeria, American Samoa, Australia, Azerbaijan, Bahamas, Bahrain, Belgium, Bulgaria, Cambodia, China, Mariana Islands, Costa Rica, India, Iraq, Japan, Jordan, South Korea, Kuwait, Latvia, Lithuania, Malaysia, Mauritania, Mongolia, Morocco, Mozambique, Oman, Palau, Panama, Papa New Guinea, The Philippines, Qatar, Solomon Islands, Sri Lanka, Tunisia, UAE, Vanuatu and Venezuela

FedEx and UPS cannot be used to ship to P.O. Boxes in any country.