Rick, you may be right; there are so many regulations that I don't think anyone can keep up with all of them, but I never heard of such a regulation by the Post Office. When we lived out in the country, that was such a state highway department regulation on state maintained roads. In fact, they actually supplied and installed the posts themselves. In our area at least, the guy who installed the posts would also mount your mailbox on it if you left it for him. If not, he put in the post and you could put your box on it later. However, on county roads, such as I was on, there were no regulations as long as it was accessible for the postal carrier. Mine was on a heavy steel pipe.
Now that we're back in town, my mailbox is embedded in a 2' square brick pedestal and there are a wide variety of types of posts and installations in the neighborhood; most, like mine, are located right in the center of my property. However, I saw in the newspaper that the Post Office is now requiring mailboxes to be at the corner of the property so that two boxes will be side by side. Such a requirement existed in Dallas in 1977, but now they just put one box in a city block with individual locking compartments for each house. In other words, it's constantly changing. /forums/images/graemlins/wink.gif