Is it really necessary for the Postal Department to print the words, “Post Office will not deliver without postage” on your package?

There are no laws against eating rocks. Why? Because no one eats rocks. If the Post Office is printing this on packages, a sufficient number of people have complained about their packages not being delivered for lack of postage that it is more efficient to just print this message everywhere.

I once overheard a woman complaining while in line at the Post Office. She apparently thought that the Post Office should be free and that you would only pay if you wanted to use UPS or FedEx to get your package somewhere faster. As the old saying goes, “Only two things are infinite: the universe and human stupidity; and I’m not so sure about the universe.”

The same reason why they have to print “content is hot” on coffee cups.
There are some really retarded stupid people out there.

The US Postal Service (USPS) sells some packing materials such as boxes and envelopes, but not all of those are sold “postage paid” (you can buy stamped envelopes for First Class mailing, and they are currently promoting the sale of their “If it fits, it ships” parcel post packages, which ship certain sized parcels for a flat rate).

If they’re selling packaging that does not include postage, then yes, it’s probably necessary for them to advise consumers that “this package was sold without postage included; postage is necessary to mail the item, and we won’t deliver without it”. It seems completely sensible to me.

Part of the practice stems from the fact that many years ago billings sent by mail were commonly mailed with a postage-paid preaddressed envelope for the payer’s convenience. Since postage costs have climbed so much in the past few decades, and more and more payments are made by means other than by mail, the expense was cut by billers. Now when an envelope is included it usually includes the same wording that you mentioned – which is obviously NOT printed “by the Post Office” – to remind payers that they need to add postage in order to mail a check or other remittance.

Apparently.

I like that Post Office message. In fact, I like it so much, I mail my local letters for free. Instead of putting postage on the envelope, I put no stamps on the envelope and I switch the TO and FROM addresses so the letter gets RETURNed TO SENDER – but that’s where I wanted it to go anyway.

Be careful with that tactic, @Charles. It’s mischievously cute, and I sort of like it myself, but the Postal Inspectors prosecute that crime (because it is a crime, no matter how petty it may seem) with the same kind of zealousness that the Secret Service prosecutes counterfeiting.

@Charles Also, sometimes the Post Office holds letters until someone comes to pay the postage on it.

@Charles. My friends in HS tried that once. The Post Office, not being completely staffed with brain-dead mutants, realized there was no way a letter was going to get from MA to WY without someone noticing it had no postage. They opened it. In it, my friend (who was a brain-dead mutant) explicitly stated that he was bored and so wanted to try defrauding the US Postal Service. The USPS returned the letter to him, along with a nice friendly notification that defrauding the US Postal Service was a federal crime, should he ever think of doing so again.