MY MOTHER USED to say never to kick a fella when he's already dragging, and Lord knows, the United States Postal Service is getting it these days from all sides. The big boys are trying to put things in the black by cutting back on labor costs and pushing for greater productivity. Some of the workers are griping about the monotony and boredom. The conservatives want to cut the budget. Nobody wants nine-digit Zip Codes. And then there's you and me, trying to get a little postal service.

The unsolicited evidence that keeps coming may way, however, makes the case that the Postal Service isn't living up to the last word in its name.

So I went out and dug up some evidence, not to prove a negative or turn the tables, but only because it's fair. I bring you herewith the evidence from some of the people who come into contact with the Postal Service -- one of the few government agencies that deals directly with massive numbers of people -- and counterpoint from Postal Service workers.

POINT: Carl Marcy of Annapolis, on the Main Post Office at Union Station Plaza:

As a regular customer at what should be the model post office in the nation, it is customary to wait in a line of 20 to 40 persons for 15 to 30 minutes to buy a stamp or seek some other service.

"For example, between 6 and 7 p.m. on the evening of May 21, I waited 15 minutes finally to reach a clerk wearing a large red, white and blue button reading "PROUD TO SERVE," who lackadaisically grumbled about how hard she was worked.

"With the support of other people in line, I tried to find the supervisor on duty, Mr. David Kukman, who would be available if I were willing to wait 15 minutes. I was offered a complaint form, which I rejected as a useless exercise to keep me quiet. I made inquiry of one of the ladies on duty in the supervisor's office as to whether it was unusual for cusers to complain about the service. Her reply: 'It happens all the time.'

"If it is not possible to provide better customer service at this main post office, I suggest that complaint and suggestion boxes be replaced with a garbage can and the "Proud to Serve" buttons be tossed in first."

COUNTERPOINT: Carole Richardson, supervisor, main office window service.

She is 43, a career employe who started as a clerk 22 years ago, the first year they hired career women employes, and thinks the Postal Service is a great service. "You can't fly, take a train, make a phone call or anything else or 18 cents," she says.

She's reminded that people would not mind paying 20 cents for a stamp if they were buying efficient service, but Richardson feels that patrons are less patient with lines because the Postal Service is a federal agency. (Actually, it's quasi-federal.)

"People feel they ought to have immediate service whereas they may be more willing to wait in line at the grocery store or bank. But I think they should be more considerate." Especially galling is the abuse postal workers receive and she says she hates it when customers toss in the caveat, "I pay your salary." Their work is hard and hazardous, she says, and they earn their pay.

POINT: Mary Ann Melchert of Washington:

"My post office, at 14th and Irving St. NW, has bullet-proof plate glass and you can't speak directly, you have to shout through it. There is no single line feeding all windows. Everybody is lined up behind whatever window is open. Our post office serves a lot of people sending foreign money orders to South America. It takes forever when you get in one of these lines. Sometimes they take their time as if it was a contest as to who is the slowest. Why can't they have arrows on the floor so nobody gets stuck in one line and to speed up the flow so everybody has a fair chance?"

Melchert dropped her complaint in the mail and, a couple of months later, received a call from a supervisor.

COUNTERPOINT: The supervisor explained that post offices are understaffed and that the Postal Service has little likelihood of getting more workers.

What she might have added is that the service that is given, although recently somewhat improved, doesn't match the complaints that are lodged from lines of impatient people. What she might have said is that Americans eveywhere complain about the situation but Postal Service officials do too little about it.

That's because the change has to come from the top officials.

John Cochran, the new head of the D.C. Post Office, is concerned about the image of the post office, and is emphasizing that the post office is a service organization. He's responded to complaints about service by intensifying training. The "Proud to Serve" buttons that irritated Carl Marcy are part of that campaign. But unlike Marcy, I don't want to see the buttons thrown in the nearest trash can. I would rather see them worn proudly -- and taken seriously.