Two government agencies that regularly catch a lot of flack find that they are good partners each April.

I'm talking, of course, about the Services of Internal Revenue and U.S. Postal.

True, electronic filing has been gaining in popularity over the years. In fact, the most recent filing season stats from the IRS (numbers there in the upper right hand corner of the page) show that more taxpayers are using e-file as the deadline approaches than in past years.

But millions still file the old-fashioned way and many of them will opt on April 17 for a trip to the post office. A lot of these filers owe the IRS and are in no particular hurry to send the agency money.

The hubby and I are in this group. And, after two years of e-filing, we mailed our return this year. Why? I just hate paying $16 bucks (that's a dollar more than last year, I think) when I can send it by mail for a quarter of that.

The cost of certified mail -- and yes, you readers who earlier called me to task for saying I simply put stamps on my IRS envelope and dropped it in the mail slot, I am using the more secure delivery method this year so I'll have proof in hand that I met the filing/timely mailing deadline -- is about one mocha Frappuccino.

I'll sacrifice one of the icy concoctions. But I refuse to give up four Frappies to pay the cost of e-filing our 1040 this year!

Payment precautions: As for our tax bill itself, I paid it electronically via at Electronic Federal Tax Payment System (EFTPS). Many of my late-filing, postal patron, tax-owing brethren, however, still like writing a check to the IRS.

Well, they don't LIKE writing the check, but they like getting the canceled document as confirmation of payment. If you're one of these folks, remember to make your check payable to United States Treasury, not the IRS.

"IRS" can too easily be altered by criminals who might intercept your payment. Those three agency initials can be changed into "I.R. Samuels" or "IRIS SMITH" or another permutation; the criminals then will claim to be the false person and cash your check, meaning you're out the money and also missed your tax-filing and payment deadline.

How those crooks got your check brings up another tax security step. Don't put your return in your personsl snail mail box for pickup. Criminals know many tax checks are going out this time of year and they can simply drive by and pull the IRS-addressed envelope from your box. Instead, follow my good example this year, go to the post office in person and send your return and payment by certified mail.

Post office pointers: And that brings us back to the IRS's long-standing old pal, the Postal Service. If you're going to wait until late Tuesday evening to snail mail your return, make sure you know which postal facility in your area will be accepting after-hours tax returns. You can use this online office locator to find the operating hours of neighboring branches.

The U.S. Postal Service also has a special tax page that includes tips on mailing your returns, the types of services that will provide more mail security and even a filing checklist you can use before you seal the envelope on April 17.

Waiting in line: I went to our local post office this morning. It was late morning, around 11:30, so I expected a bit of a lunch rush. However, I was a bit taken aback by the gathering of customers.

Our branch has one of those "take a number" machines you typically find in delis. The tab I pulled out was 90; the electronic counter on the wall read 64. Whoa! Luckily, several impatient people in the 65-to-89 group apparently left, so I made it to the counter in just half an hour.

Before then, though, it was clear what most of us were there for. One of the counter workers had the patter down, well, pat. Handing people their certified mail slips and a pen (none of the lobby counters had any writing instruments), he automatically recited, "Internal Revenue Service Center, Austin, Texas, 73301."

When I serendipitously made it to his window, I asked if he was ready for tomorrow and he told me that Tax Day is actually just about the fourth busiest day the agency faces.

I suspected the Christmas mailing season was the busiest, particularly that week before, and he confirmed that. But I thought mid-April would come in second.

No, he said, Mother's Day is the next heaviest traffic day, at least it has been for years at that facility. Coming in third is Valentine's Day.

And the annual tax due date is fourth. I guess e-filing really is taking hold.