Am I wrong? (postage thing)

[Leila]

Have the rules changed on me? Isn't it the sender's responsibility to provide enough postage on an item before putting it in the mail? More and more lately I've been getting mail that my postal carrier attaches envelopes and snarky notes about owing HER postage. Sure, it's piddly amounts (the most was just under $1, the least 10¢), but what ever happened to sending it back when there's not enough postage? C.O.D. is one thing, but the item today? I paid $2 for shipping and they only put 82¢ postage on it.