The postal service may not be the most alluring career choice, but at least it affords one plenty of time to think. And Albert Lippincott -- known by his mock-superheroic handle, Mailman -- has plenty to sort through on his route in fictional Nestor, N.Y. The burg (which, in Mailman's mind, assumes mythic proportions) is home to his aborted science career; his nemesis/former adviser, a best-selling author and unrepentant charlatan; his nervous breakdown and failed marriage; and unsuspecting residents whose mail he can't stop stealing. A small-town Odysseus whose final destination is unclear, Mailman directs his inchoate rage at everything from bureaucracy to corporate-speak to bumper stickers. At the heart of his cynicism is a desperate yearning for love that makes ''Mailman'' as emotionally devastating as it is scabrously funny.