ziploc baggy? Maybe. I have no idea, but look up some video of unboxings of snails on youtube just to be sure and see how businesses ship them.
When I bought my ramshorn snails at my LFS in person they bagged them just like fish, part water with captured air filling the bag. If you did go the Ziploc route, I would at least double bag it in case the water leaks out. Not sure if they need to be submerged in water or just enough to sit in, need air tight bag filled with trapped air? No idea lol, just bringing it up so you can consider.