"Neither rain, nor sleet", etc - all well and good within reason.

But when the State Highway Department throws snow a couple of feet high in front of your mailbox, is it the obligation of the U.S. Postal Service to clear it away so they can put a bunch of advertising circulars in your box? Or is it the obligation of the homeowner to clear it away if they want their mail delivered safely??

Neither the post office or the homeowner has any obligation to keep the area by the mailbox cleaned out at all times. I sure wouldn't want to see my mail carrier stuck in the snow in front of my house because she felt it was her obligation to deliver the mail to me everyday, regardless of whether it was safe to do so, or not.