On 21 Jan 2016 17:43:05 GMT, KenK wrote:

It would be nice to have something to use with my rural mailbox to tell if
the mail has come when I don't have any outgoing. I oten forget to check by
that late in the afternoon - busy with other things like making my supper.
My delivery time varies, I suspect because different deliverers. Currently
it's late in the afternoon, sometimes after 4 PM.

I'e not tried Googling yet.

Way back in 1957 there were lots of devices that did this. They set
a yellow flag that we could see from our house 120 feet from the box.

Oours only had 3 metal parts counting the yellow flag, plus a screw
and a metal weight. Ours used the weight to make the flag go up.
Others used a mechanical arm forced down by the door to pull up the
flag.

I think a radio would be fine if you couldn't even see the mailbox,
but otherwise it's far more cost and trouble than need be.

TIA