There's a
damn good reason for that. Several years ago there was a rash of
armed robberies of UPS and USPS personnel by criminals trying for an easy
buck.
The Swiss Post delivery folks are happy to accept cash around here and I
never tried any other payment method. But then, I _am_ living in Switzerland,
which is a very peaceful place.
Last time (which admittedly was over a year ago) I had a parcel delivered
by UPS with import duty to be paid on it, the driver told me he could
accept cash or cheques, but not a credit or debit card. That may have
changed by now.
-tony