(FORTUNE Magazine) – For the U.S. Postal Service in New York City, the Christmas mail rush was dress rehearsal for a period that's just about as hectic: April's proxy season. Proxies will boost the average number of pieces of mail arriving in New York, where most proxy-solicitation firms are located, from seven million a day to 9.5 million. The brunt of the extra work will fall on clerks in New York's 168 sorting stations. Companies expecting big proxy deliveries generally pick them up by truck, thus sparing the mailman (or mailwoman; females account for 57,409 of the nation's 268,238 mail carriers). Not that carriers will have had much of a break from Christmas, which itself followed hard on the bulky September and October catalogue delivery season. January is another delivery peak, this time for corporate and individual tax forms and white sale announcements. Besides the weight of it all, carriers face other hazards. Dog bites are common, though in fiscal 1988 they were down to 2,781 from 1981's all-time high of over 7,000. One reason for the drop: The post office now stops delivering in an entire neighborhood if a threatening dog continues to run free. Neighborly pressure usually persuades the dog's owner to keep it leashed. George Davis, safety director for the National Association of Letter Carriers, likes to remind his carriers of safety instructions: ''A dog usually charges from behind you. You're supposed to stop and face it. But somehow the only thing you remember is to run and keep the mailbag behind you.'' Davis has been bitten twice -- from behind. Other threatening fauna include rattlers in metal mailboxes in West Texas, frogs on the wet spring roads of New Hampshire, and wild turkeys along the byways of the South. A Memphis rooster, mistrustful of the carrier's intentions toward his hens, used to attack him whatever the season. That was back in the 1960s, but the rooster remains part of postal lore. In New York one danger could be truly deadly: Mail carriers from the Canal Street station have found used hypodermics in mailboxes. To protect themselves from catching AIDS from an accidental puncture, at least two carriers have worn chain-mail gloves. Robberies are also more common than in the past. Even so, says Ben Johnson, a union official, ''postmen still go alone where cops won't go without backup.''