Other television programs drawing inspiration from letters, such as Trust in China, which was first broadcast on China Central Television early this year, and that have focused on letters of more recent vintage, have also been well received.

Zhu Anshun, an expert on traditional culture based in Beijing, said it is important for people to understand and value a heritage of correspondence.

As a form of traditional culture, letters have a long history and have played an important role in traditional Chinese life, he says.

There used to be people whose profession was letter writing, who were paid to write for those who couldn't read and write, and a Chinese saying gives an idea of the esteem in which written correspondence was held: "A letter from home is worth ten thousand pieces of gold."

A great many specialized terminologies, such as terms for different periods of the year, for addressing or greeting people of different ages and identities, were developed in the epistolary art.

"It was not only an important way by which people were connected, but was also a literary phenomenon," Zhu says.

Many personal letters, from early ones written on bamboo slips to those on paper, have been passed down. Some have become important sources for historical research, and others have been well known by generations of Chinese as literary gems, excellent calligraphy works, or simply famous specimens of a certain person's handwriting, Zhu says.

In modern times some of the better-known literary works come in the form of private letters, too, such as Letters Between Two, the correspondence between Lu Xun, China's greatest modern writer, and his wife Xu Guangping from 1925 to 1929.

Readers can trace in them the gradual change in their relationship, and they also reveal their thoughts on literature, education, politics and their outlook on life.

"These are evidence of personal letters' significance in expressing human feelings," Zhu says.

Letters as a traditional way of communication should be encouraged in the modern age, as they have a lasting appeal and cultural significance, he says.

Huo Chongqing, a calligraphy aficionado of Wuhan, Hubei province, says he often writes letters using a brush and sometimes in classical Chinese, and uses a lot of traditionally used terms and expressions, too.

"There is a lot of culture in letter writing. You can find beautiful rhetorical expression and poetic language in the traditional letters, and they should not be lost."