IT ARRIVED in the mail looking like a giant cigarette pack and my inclination was to write it off as just another publicity gimmick and to chuck it into the same receptacle I tossed my cigaretts into five years ago. But the 1980 Virginia Slims American Women's opinion poll, despite its associaton with the tobacco industry deserves far better treatment than that.

The poll, fourth in a series conducted by the respected Roper Organization, provides the most extensive and enlightening documentation yet available for the changes we've been feeling all around us. It establishes a widespread shift toward a more egalitarian life style since 1970 -- a shift that has occurred in the workplace and in the home, and among older as well as younger people.

Some 3,000 women and 1,000 men, 18 years and older, were chosen in a representative smapling across the country, interviewed for about an hour and asked 90 questions.

The 1980 results not only compare attitude and life style changes over the past decade, but they compare changes in attitudes between men and women.

The single most overriding conclusion you get from the poll reported is that the American women's movement is no longer a fringe trend, fanciful experiments such as living together that are being tried out only by young people. The American women's movement has been mainstreamed. In 1970 only 40 percent of the American women supported efforts to strengthen and change the status of women in society, and most of them were younger women. Now, 64 percent of American women support such changes. Men have changed their attitudes equally dramatically, with 64 percent of them supporting an improved status for women now, compared with 44 percent in 1970.

The greatest change has come in the attitudes of older, less educated women, the group that was most opposed to the women's movement in 1970. Now, 55 percent of these women favor improving the status of women and now, four out of five women polled said they were committed to furtering women's rights.

Women have become increasingly aware of sex discrimination, with 43 percent of them now believing that men have a distinct advantage in life. Women are particularly conscious of discrimination against women in getting executive jobs in business, government and the professions. More than half the women polled believed they would be discriminated against in getting such jobs, and nearly half the men who were polled agreed.

Opinion also has shifted strongly toward equality in marriage, with a majority of women and almost half the men saying they believe now that the most satisfying and interesting way of living is to be married, with both spouses working and sharing homemaking, and child-rearing responsibilites. As recently as six years ago the majority of men and women favored the traditional, one-income (father's) marriage. And there is more tolerance now from both men and women toward the idea of a man staying home and raising the children while his wife works.

A lot of the men polled said that -- at least sometimes -- they help do household chores other than taking out the garbage, mowing the lawns and doing household repair jobs. More than 60 percent of the men said they sometimes or frequently keep their rooms clean, wash or dry dishes, help clean the house and help with the cooking. Half even said they make their own bed. But fewer than half said they helped take care of the children and did their own laundry, and as for mending clothes, forget it.

Motherhood had continued to decline in popularity. A majority of the women now would limit their families to two children and 82 percent of the women said children are not necessary ingredients for a happy and satisfying marriage.

It appears that the children that are born are going to be raised a lot differently from their fathers and mothers. The days in which the sons did the yard work while the daughters vacuumed and changed the beds are over. Sex stereotyping in household chores had declined in the past six years to a point where the overwhelming majority of mothers believe that both boys and girls should be expected to help with all household chores. While only 39 percent of the women polled in 1974 believed that boys should help with that most traditional of female chores -- mending clothes -- now 56 percent of the women would have their sons mend their clothes. (The 1980 poll didn't survey men on this topic, so it is not possible to see whether they agree.)

While men and women repeatedly expressed a preference for an egalitarian life style and an expectation that it will flourish in the future, the survey found that the anti-ERA forces have eroded some of the support for the constitutional symbol of the new way of life. Passage of the Equal Rights Amendment is supported by 51 percent of the women now, compared with 55 percent in 1975, and by 52 percent of the men, compared with 68 percent in 1975.

The antiabortion movement seems to have had much less impact. A large majority of men and women (74 and 76 percent) said that where abortion is legal, it should be a decision between the woman and her doctor. Only 37 percent of the women and 31 percent of the men polled says laws permitting abortions should be repealed.

The questions raised and answered in the poll are the kinds of questions a lot of us have been asking as we have changed our way of living during the past decade, wondering all the while if it's just us and our friends, or whether there are a lot of husbands across the country joining us in the kitchen. The evidence now is that the new life style is becoming a majority way of life.

An overwhelming majority of the women surveyed have rejected the term "Ms" -- that symbol of independence that had such a tough time getting into the language only a few years ago. But the poll shows definitively that while women have eschewed the term "Ms" they have embraced the values and life style it stands for.