Neither snow nor rain nor heat nor gloom of night keeps the US mail from reaching its destinations — but a frightening vehicular mishap sure can.

This US Postal Service tractor-trailer plunged off a busy South Jersey highway early Friday, leaving it dangling nearly upright off an overpass and causing traffic backups for hours.

The rig collided with a vehicle in the northbound lanes of I-295 in Mount Laurel, just east of Philadelphia, after 3 a.m. and went over the edge, with the cab landing on a street 20 feet below, New Jersey State Police told Philly’s NBC affiliate.

The unidentified driver, 50, of Vineland, NJ, miraculously suffered only minor injuries. The occupants of several other vehicles involved in the crash were treated for nonserious injuries, authorities said.

Hazmat crews responded because fuel spilled onto the road below from the truck’s shattered tanks.

The US Postal Inspection Service also went to the scene to make sure the mail was secure, officials said.

Church Street, below the bridge, reopened at about 12:35 p.m., but crews continued to block a lane amid the repairs and cleanup effort, police said.