I have family members who are letter carriers. They deliver in all weather despite road conditions. Icy walkways are about the only exception. Our mailman always delivers but we make sure to shovel out and snow blow out as best we can the mailbox. He does deliver to everyone, regardless of conditions, who has mail even if they haven't tried to clear out their mailbox. We do b/c DH works for the post office but not as a letter carrier.