The Plan C site gets into a lot of this -- it's generally already a crime for doctors in restricted states to prescribe mifepristone and misoprostol (the two drugs needed for medication abortion) for most elective abortions. Folks have reported having success with something similar to what your friend did, but for abortion pills -- using a legal U.S. telemedicine service and picking up in another state. I'm would guess there will be attempts to try to legally restrict that kind of travel/PO Box situation in the future, though!

Another resource that Plan C lists is Aid Access, which has a Dutch doctor write prescriptions that are then sent to an Indian pharmacy and then to the U.S.. Plan C also lists some sites in their directory that don't require a prescription, as well. None of this comes without legal risks but it's often a gray area -- just acquiring pills isn't generally a crime (right now) in and of itself, and USPS says they won't proactively intervene.