I can not put the owl mailbox anywhere but the ground. I usually place the mailbox higher up on a house. For example, I would place it on a post or upper floor in a townhouse. I have removed my owl mailboxes and tried to place them anywhere but the ground. The mailbox stays red and when trying to place it, I get the error "not allowed to place this here". I have tried on all of my characters, but one. Doxazo from AAU Kaylin Server. This bug seems to be on both AA and AAU. I didn't discover this until 12/17/20. That is when I resubbed to AA. Prior to my 1 month lapse in subscription, I had my mailboxes where I wanted them. This seems to happen with different types of houses. I have noticed it with both types of bungalows, tree houses, beanstalk house, mushroom house, townhouses and farm houses. This every time I have tried. This bug is annoying, so I will say 3 for the severity. My OS is the latest version of Windows 10. I have 16gb of ram. My gpu is Nvidia 2060 super from EVGA. My desktop is directly connect to my ATT residential gateway. My laptop is connected using wifi connect to the residential gateway.
It's not a bug, there was an intentional change to furniture that says "yard" for placement. You used to be able to put all of it on the edges of a structure. Now you can only put it in a yard.