Where I live, in unincorporated Alameda county CA. mail is delivered to a slot in the wall by my front door. Very good. However sending mail is getting hard. Street side post boxes are nearly gone, and the post office is a mile and a half away. I most often just take things to work where we have a nice mail room and a very helpfull young lady who will stick stuff in the outgoing for us.
The post office claims you can leave outgoing mail clipped to the slot cover, but you may as well hand it to the local gang member as leave it out side. Speaking of rural mail boxes though, somewhere here we have a gizmo with a small transmitter that you put in the far off mail box. There is a receiver you put where you can hear it. Somehow, and it may be light activated, when the mail box is opened, the receiver beeps. Never seemed to work very reliably when informally tested here in the lab. Tom Fowle