Originally Posted by Skladfin
"(2) An officer may not open or cause to be opened an imported mail item that weighs thirty grams or less unless the person to whom it is addressed consents or the person who sent it has completed and attached to the mail a label in accordance with article RE 601 of the Letter Post Regulations of the Universal Postal Union."
... well that's weird, that means that they can't check stuff at all.
or did I think wrong?
You thought wrong. Most things you import will be over 30 grams, things that aren't over 30 grams are letters (or an envolope with about 150 .2g BBs).