Opossums are not on the rabies suspect list. They have very primative nero-systems (the pathways which rabies uses to travel to the brain to replecate it's self), and their body temperatures are much lower than modern mammals. Their bodies do not readily host or support the rabies virus. Infact, I believe the only documented case of an opossum with rabies was an individual that was actually bitten directly on the head, which essentially would have injected the virus directly into the brain matter allowing it to then replicate, and give the animal the ability to spread the virus. Opossums are considered fur-bearing animals, and they may fall under that umbrella of protection, but it would not be illegal to relocate an opossum due to rabies. Especially since opossums are mainly nomadic, and do not stick around in one place for extended periods of time.
ACO for a major city in North Texas, and permitted wildlife rehabilitator.