They cant do anything to you, if they find weed going to you. On the other hand, do not put the actual return adress on it, because the may be able to do something to you then. Definitely vacuum seal it, and wipe the bag off afterwards. Put it in very thin cardboard if it is a few grams or a box if it is alot, then put it either in envelope if grams or just use box for alot. Not really a chance of anyone getting in trouble then.