Heh, but not all the countries gives you the same services ..... as example, we don't have any service like "delivery confirmation only", here in Italy, it's available only as extra service on a tracked mail ..... you can send a standard letter (envelopes only, boxes costs much more), called "posta prioritaria", also if it have no priority

, for from 3.30 Euro (less than 50 grams) to 25 Euro (from 1 to 2 Kg), with no confirmations at all (you send, and *maybe* the destination receive it) ..... if you want a tracking number or a deliver confirmation, the only service is "raccomandata" (tracked mail), that go from 7.30 Euro (less than 50 grams) to 29 Euro (1 Kg) for the tracking service only (no confirmation), or with 0.75 Euro extra, you can also receive the delivery confirmation, but NOT only it (i mean, you can ask for the delivery confirmation ONLY if you pay for a tracked mail, NOT for a standard mail like in the USA)
And, as far as i know, some countries don't have also tracked mail services .....
Anyway, the points you mentioned are very important, and if only more peoples will observe them, we may have much less scammers that can do their "work" with success :beer:
BTW, about cash sent through letters, i asked my postal office, cause i remembered i had read something about it, times ago, and got a confirmation ..... is already 2 years that here is prohibited to send ANY cash for ANY reason, in letters or envelopes, through postal system ..... and other than this, if money become found inside letters, it's seized, an internal investigation is started against the sender office, and if found that the postal office employee was knowing that the content of the letter was cash, it become fired (this cause, here, in the past, too much money was stolen from mails).