UPS:
Packages that contain any of the prohibited articles listed in the applicable Service Guide or the Terms are subject to additional charges, including but not limited to a Prohibited Item fee. Packages that contain restricted articles not in compliance with all UPS policies and procedures and applicable laws and regulations are also subject to additional charges, including but not limited to a Prohibited Item fee, if found in the UPS system. Such charges apply in addition to all other applicable Charges and in addition to any other rights to recovery UPS may have under the Terms or applicable law or regulation. UPS reserves the right in its sole and unlimited discretion to dispose of such Packages, submit such Packages to governmental authorities, or return such Packages to the Shipper solely at the Shipper’s risk and expense. The Shipper shall remain responsible for all Charges whether or not such Packages are delivered. The Shipper agrees to reimburse UPS for any costs or expenses incurred as a result of Shipper tendering any such Packages to UPS, including but not limited to all disposal fees.
A little more serious than 3 ketchup packets. Also, UPS has the right to inspect any packages mailed with them without your consent. Can you read that yourself or do you need me to link that too? If your method is to be 'vague' so as to not 'lie', you are already mailing in bad faith because you know what's in the package. If you do get caught, please let me know how your 'playing dumb' trick worked out. Until then, you might want to let the adults do the talking on what is and is not correct.
Some folks on this forum must be the 'fact-checkers' from the media I've heard so much about. Whatever you do, don't listen to internet people and read from the source material (which have all been linked for USPS, Fedex, UPS, and the ATF). If you read the rules or regulations and don't understand them, bring them to the postmaster or help counter and have them explain it. Considering that mailing a firearm the wrong way can be a felony, you shouldn't hang your hat on the advice of the 'wise guys' found here, or on any other forum.
For example; if you ask in a thread whether or not you can mail a rifle that has a receiver date of '1899' directly to someone's front door, and some old fart tells you 'Yes'. Only that that old fart forgot that the 'antique' cutoff is date is 1898, and not just 'pre-1900'. If that were to get caught for any reason, a prosecuting attorney won't be so "free-thinking" as some of the folks here, and playing dumb as MikeIke suggested won't work very well. The details between 1898 and 1899 matter, as do the shipping regulations (which change often). The odds of getting caught shipping wrong are low, but not zero. I once had an interested buyer here on gunboards ask me to ship an 1899 Gewehr 98 directly to him "because 8's sometimes look like 9's" (exactly what he said to me). I am not willing to commit a felony for the convenience of some random internet guy wanting to save $20 for an FFL fee. The amount of confessions in this thread of how some people ship their guns goes to show many people disregard the consequences of what they are doing to just save a small FFL fee and bank on luck that it will pay off. As far as I'm concerned, the mods should delete all the responses in this thread except for the links to the rules & regulations for the shipping companies and ATF. Just because someone has a way of doing things that has worked for them before, doesn't mean it is the right way to do it.
For someone who wants to do things the right way, get familiar with the rules yourself, or have an FFL ship for you to take that liability off your shoulders. Heck pass the shipping fee on to the buyer - no skin off your back either way.