The US Postal Service vows that "neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds." But we must look to its rival UPS for video evidence to this effect.
Last January, Walt Gorczowski recorded footage of a UPS driver going the extra mile to get a package up to Gorczowski's house. He describes the incident:
Last week we had an ice storm. My driveway was smooth, wet ice... super slippery. I heard the UPS truck pull up so I opened the garage and told him to just leave the package at the sidewalk and I'd figure out a way to get it, but he insisted on getting it to me. Above and beyond... this guy is awesome.
-via Twisted Sifter