Free delivery exception
The delivery of letters without compensation and without the affixation or payment of any postage is also allowed; under 39 CFR 310.3(c) by third parties; and under 39 CFR 310.3(b) for one's own letters which includes regular employees only delivering company mail. Thus, it is not a violation of the PES if one delivers a letter of one's friend even without affixation of postage or if a company has one of its regular employees delivery mail that originates from the company to its customers. Regarding the personal delivery without compensation it is important to note that compensation is considered to include barter and goodwill. Thus an individual or business who receives a benefit for the delivery of letters does not fall under such a free carriage exception. For example, if you ask your friend to deliver a letter and you say, "When you get back I'll take you out to dinner," such carriage is not considered without compensation; in such a case one would be required to affix and cancel a sufficient amount of postage to the letter. Another example not falling under this exception would be a business that is carrying letters "free of charge" in the hopes of building business or incidental to some other delivery as an accommodation for its customer; this use would also require the affixation and cancelation of a sufficient amount of postage to be in compliance with the PES.
Cargo delivery exception
There is also an exception for the delivery of what otherwise may be considered a letter if it is sent with cargo and the letter is somehow incidental to the ordering, delivery or shipping of the cargo [39 CFR 310.3(a)].
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