Instead, a mailer must present such a mailpiece to an employee at a Post Office™ retail service counter. These stamped mailpieces also may not be picked up by city, rural, or highway contract letter carriers for delivery, either from an individual or through Pickup on Demand ® service. Under the revised standards, domestic and international mailpieces that weigh more than 10 ounces or measure more than one half-inch in thickness, and bear only postage stamps as the postage payment method, may not be deposited into collection receptacles, including street, lobby, and apartment boxes, or other unattended locations.

The USPS current regulation reads (emphasis ours): Note that if you use PBS Printed Postage, the USPS's '10-ounce or 1/2 inch thick rule' described below does not apply and you do NOT have to mail from the Post Office. If you do not use electronic postage (if you use postage stamps to mail), then whether you have to mail from the PO depends on the weight of your package. You do NOT, if you use electronic postage (such as our 'PBS Printable Postage').

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