USA - Attempted Possession?

[Jacco]

Hey,

Let's take a hypothetical situation.
Supposed that swim ordered, say, 2C-I overseas. The DEA caught the package and decided what to do with it. Although they normally just send love letters, this time they want to bust the orderer.

Swim is familiar with what they usually do in these situations. They lure the purchaser into the post office, then have a DEA agent present the package. Swim suspects that the reason they do this is to transfer possession of the drug to the user, so they can charge him with possession of scheduled chemicals.

However, what if swim suddenly said "I don't recognize this package and I'm not going to take it?" Would the DEA be able to stick anything to him? Is attempted possession illegal? Does swim really have anything to fear in ordering drugs and having them intercepted? It'd be interesting to see the precedents unfold.