Get the biggest mailbox you can down at the road, and get to know your mailman. If they like you, most of them will take care of you. They deal with a lot of a-hole types in their day, and if you aren't one, you stand out from the crowd.
My mailman LOVES my big mailbox, but when something won't fit, he brings it up and sets it on the bench by the porch. Rarely do I get a notice to pick up something at the post office. Added: My mailman is also one of my best egg customers...like I said - make friends.
As far as UPS and FedEx - don't worry. They too will figure it out.
As far as UPS and FedEx - don't worry. They too will figure it out.