Her daughter will throw the gifts out, if she thinks they didn't come from the high end stores, or she won't let her see the grandkids for awhile to "punish" her for not shopping high end for them.

As he should. He also canceled it.I asked the town post office if they could put a Christmas card in my grandmas box. Knew I wouldn't run into her and the box was right there in the post office so no sense in mailing it. He did, but made me pay for a stamp, lol.
I think leaving something in the box for the carrier is OK because it is "outgoing". The illegal part is someone besides you or a postal employee putting something in the box. A Fed EX (maybe UPS??) carrier got in trouble for putting something in a mailbox. The carrier opened the box and there it was. Post Master called the delivery service, which ever one it was.My deliveryman never complains when I put a card and 20$ in my mailbox for him each year (except the year he was on vacation and the backup rural carrier took it) and I don't have to pay for a stamp![]()
Sorry to be the bearer of bad news but taking cash or something that can be converted to cash is strictly forbidden. The value of any gift "incident" can not exceed $20. Find out if there is somewhere they frequent that has gift cards.
I do not think there is a specific limit to how many times a year you can give a gift to your favorite postal employee(s). Thus, if you are getting really great service, above and beyond what one might expect, you can thank them multiple times a year. I don't know if that happens often thought.
That can be a rough one. USUALLY they will bring it to the door and leave it unless there is a signature required (then they leave the notice). If they aren't, unless they get cash gifts for Christmas, ... not good.You could also take it down to the PO and ask that it be given to your regular carrier. I've done that a few times.
I used to have problems with USPS not delivering my larger packages and instead leaving a note for me to go pick it up at the local office. That simply does not work for my schedule, because it closes right after I get off work, and I can't get there.
20$ a year and I get amazing service.
Of course, given your driveway, I can see where they wouldn't try to deliver to the door in winter conditions.