When I recently asked the U.S. Postal Service to hold our mail during a vacation, I thought I was giving the federal government a simple task. After all, our carrier wouldn't have to worry about rain, sleet or snow deterring him from his appointed rounds. He could just skip our house for six straight days.

Nonetheless, Postal Service workers managed to misplace our mail. They found it a day later. But maybe they shouldn't have bothered.

When it finally arrived, I began to realize why the Postal Service, that semi-independent federal agency with a civilian workforce almost as big as the Pentagon's and a mission that predates the Constitution, may be in more trouble than its leaders recognize. The problem of disappearing mail, it turns out, isn't just about misplaced stacks of letters and catalogues. The mail we used to crave is vanishing from our mailboxes -- because it isn't being sent anymore.

If "you've got mail" these days, it's likely e-mail. "Snail mail" isn't just slow, it's literally evaporating. For three straight years, the Postal Service has observed an unprecedented drop in the amount of first-class mail. Electronics -- e-mails, faxes, online bill paying and cheap long-distance calling plans -- are killing it. Most of the mail that's left in your mailbox is disappointing. Dull. Boring. Routine. Trash. (Though some people insist they love the catalogues.)

Take my weeklong absence. Most of what I finally got after my mail was discovered stashed under a letter carrier's rack was bulk mail. What critics call junk mail totaled 37 pieces in all -- including two shoe catalogues, several cell phone offers and some Chinese takeout menus -- easily outnumbering my week's worth of 26 first-class letters and seven magazines.

Only four of the letters were personal greetings mailed at the 37-cent rate. All were thank-you notes to my wife for a party she had hosted. The rest of the first-class mail was impersonal business mail that arrived at discounted rates. (Big mailers get price breaks for "pre-sorting" their letters by Zip code before they mail them. It's a rare merchant who uses 37-cent stamps these days.) Among those bulk-rate letters, there were two checks we were happy to receive, seven bills we were pained to see and four statements of various financial accounts. It was hardly the stuff that people used to race to their mailboxes to retrieve. No warm greetings from a long-lost friend, no fretful note from a relative, not even a cheery "wish you were here" postcard from a vacationing acquaintance.

For years, postal officials denied that e-mail would change their world. Now, faced with declining letter volume -- in 2003, first-class mail dropped by 3.3 billion pieces -- the Postal Service has finally realized that its right to a monopoly on first-class letters probably isn't worth the paper the Congress wrote it on in 1794. "All types of correspondence mail have declined over time," said a recently released household mail survey by the Postal Service. "Most notable, however, is the decline in personal correspondence between households."

Advertising mail, a competitor to newspapers, radio and TV, is the one bright spot in the nation's mailbag, the only major growth part of the mail. But because of those bulk mail discounts, it pays less of the Postal Service's fixed costs than the occasional letter from the Postal Service's mythical "Aunt Minnie." She is the customer who sends her letters one at a time and always at the highest rate. First-class letters from her and from the nation's businesses have underwritten the Postal Service's hefty institutional costs for decades.

Trouble is, as the President's Commission on the U.S. Postal Service reported last year, Aunt Minnie isn't writing that many letters these days. Indeed, letter writers are a dying breed. Younger families are writing even less than their parents did, the Postal Service says. They probably depend on the Internet for communications that used to be part of the postal monopoly. More troublesome for the Postal Service's bottom line, business-to-business mail is also falling.

It doesn't take much analysis to realize, as the presidential commission did, that the Postal Service is facing a crisis unlike any since its founding in 1775 by the Second Continental Congress. Mail volume is likely to keep declining, the panel said, while the big agency's costs, most of them directly linked to 700,000 employees who handle the mail, will continue to soar.

Unless Congress acts on proposals to allow the Postal Service to adjust its prices and products more rapidly, the bipartisan commission warned President Bush, the service faces three possible fates: It will have to "dramatically roll back service, seek a rate increase of unprecedented scale, or fall even further into debt, potentially requiring a significant taxpayer bailout." No one is talking about closing down the U.S. mail, although a number of foreign countries have privatized their postal operations.

Congress, however, apparently will do nothing about the agency's financial problems. This summer lawmakers were poised to pass legislation that would give the Postal Service more freedom to adjust its prices more quickly, but it was pushed aside after the 9/11 commission called for immediate action on revamping the nation's intelligence agencies.

But Congress had already decided much earlier that snail mail can wait, and wait. After the anthrax letter attacks of 2001, scores of lawmakers put notices on their Web sites asking their constituents not to send letters to Capitol Hill anymore. Send faxes or call, they urged. Mail takes too long and may be too dangerous. If you must write, send letters to our offices back in the district. So, it probably shouldn't be too surprising that saving the nation's mail system isn't exactly a high congressional priority.

Unless the lawmakers suddenly change their minds before their scheduled Oct. 1 adjournment, postal customers will get the bad news about the mail well after the November elections. By avoiding any postal legislation, Congress has laid the groundwork for what some mail industry lobbyists are calling the biggest "stamp tax" the country has ever seen.

The next rate increase has long been scheduled for 2006. Some expect a first-class stamp will be 41 cents, perhaps even as much as 45 cents. In total revenue, it seems certain to be one of the biggest increases the Postal Service has ever imposed. When it became an independent agency in 1971, first-class stamps cost 8 cents, and the service has more or less managed since then to keep stamp prices in line with inflation. But the frequency of rate hikes has increased sharply in the past 12 years, and the presidential commission was clearly worried that postal officials will be unable to keep future hikes below the inflation rate. The fundamental problem remains that the Postal Service must charge more for something that is free to Internet users.

Meanwhile, despite his own commission's report, President Bush has actually performed some budgetary sleight of hand this year to force stamp prices higher. His latest budget includes an accounting change that requires the Postal Service (meaning stamp buyers) to pick up the entire retirement costs for postal workers' military service -- about $27 billion. Although all other federal agencies must also give their workers credit for time in uniform, none of them have to pay for it through retirement costs. Postal officials say making rate payers shoulder the burden of this benefit puts the Postal Service at a competitive disadvantage with private companies like FedEx and UPS, which already have lower personnel costs.

Worse still, the rule is retroactive to 1971, when Congress made the Postal Service independent; this provision alone will cost customers $17 billion. A number of Republican and Democratic lawmakers who oversee the Postal Service have said they disagree with the new rule, but there is no congressional action to overturn it in sight.

There is a long tradition at 1600 Pennsylvania Ave. of letting the Postal Service twist in the wind. Ever since Richard Nixon succeeded in kicking the old Post Office Department out of his cabinet in 1971, the Postal Service has been something of a big, unwanted chunk of the federal bureaucracy. Charged with making it on its own, without the direct support of federal taxpayers, the agency has stumbled from rate increase to rate increase. The huge agency has never had an advocate with a pulpit as big as its problems.

Postmaster General John E. "Jack" Potter, a career postal worker and the nation's 72nd postmaster general, has been amazingly successful in squeezing savings out of what remains a massive bureaucracy and the only part of the federal government that claims to touch everyone, every day. But Potter knows that there are limits to how much he can save by rearranging the locations where letters are canceled or delaying construction of new post offices.

Whatever he does to change the agency's structure, he knows those changes alone won't bring back the missing mail.

Author's e-mail: bmcallister@cox.net

Bill McAllister is a former Washington Post reporter who has covered the U.S. Postal Service for almost 20 years. He is currently Washington correspondent for Linn's Stamp News.