Not everything
I recall shipping my family a box of presents- all gift wrapped- and the customs agents, though they opened the box, did not inspect the wrapped gifts.
The package was sent by a female. From Asia
She even wrote 'I love you' on the box....and 'Merry Christmas'.Could have just as easily been 'Happy Birthday' or 'Happy Passover' etc.
Such holidays come often.
Anyway, the package in mind contained ONLY harmless gifts-
and, bless them, the customs agents did not open the children's presents- who would- only a nasty, scrooge type- and no customs agents want to feel like one of those!!