Postmark Ganymede by Robert Silverberg - Consider the poor mailman of the future. To "sleet and snow and dead of night"—things that must not keep him from his appointed rounds—will be added, sub-zero void, meteors, and planets that won't stay put. Maybe he'll decide that for six cents an ounce it just ain't worth it.

"I'm washed up," Preston growled bitterly. "They made a postman out of me. Me—a postman!"

He crumpled the assignment memo into a small, hard ball and hurled it at the bristly image of himself in the bar mirror. He hadn't shaved in three days—which was how long it had been since he had been notified of his removal from Space Patrol Service and his transfer to Postal Delivery.

Suddenly, Preston felt a hand on his shoulder. He looked up and saw a man in the trim gray of a Patrolman's uniform.

"What do you want, Dawes?"

"Chief's been looking for you, Preston. It's time for you to get going on your run."

Preston scowled. "Time to go deliver the mail, eh?" He spat. "Don't they have anything better to do with good spacemen than make letter carriers out of them?"