On the other hand, some of the family's impatience with the public is justified. When I use Federal Express, I accept as a condition of business that its standardized forms must be filled out in printed letters. An e-mail address off by a single character goes nowhere. Transposing two digits in a phone number gets me somebody speaking heatedly in Portuguese. Electronic media tell you instantly when you've made an error; with the post office, you have to wait. Haven't we all at some point tested its humanity? I send mail to friends in Upper Molar, New York (they live in Upper Nyack), and expect a stranger to laugh and deliver it in forty-eight hours. More often than not, the stranger does. With its mission of universal service, the Postal Service is like an urban emergency room contractually obligated to accept every sore throat, pregnancy, and demented parent that comes its way. You may have to wait for hours in a dimly lit corridor. The staff may be short-tempered and dilatory. But eventually you will get treated. In the Central Post Office's Nixie unit--where mail arrives that has been illegibly or incorrectly addressed--I see street numbers in the seventy thousands; impossible pairings of zip codes and streets; addresses without a name, without a street, without a city; addresses that consist of the description of a building; addresses written in water-based ink that rain has blurred. Skilled Nixie clerks study the orphans one at a time. Either they find a home for them or they apply that most expressive of postal markings, the vermilion finger of accusation that lays the blame squarely on you, the sender.