Alipay, Alibaba's Paypal-like division, which is not part of the IPO, is the world's largest payment processor with a payment volume of 519 billion U.S. dollars in 2013.

At the end of 2013, Alibaba said it had 231 million active monthly buyers, up 44 percent from a year earlier. For the nine months ending Dec. 31, Alibaba generated a net income of 2.9 billion U.S. dollars on revenues of 6.5 billion U.S. dollars, according to the document.

Alibaba, keen to expand out of its core online retail business, has increased its reach to include shopping malls, home appliances, mapping services, media and financial services through a series of acquisitions in the past year.

Hong Kong was once the top choice for Alibaba's IPO but the plan was aborted in part because of Hong Kong's Securities and Futures Commission's opposition to Alibaba's unique corporate structure.

Under Alibaba's statutes, the company's partners are able to nominate and control the board, which is a challenge to the one share - one vote standard applied in Hong Kong.

On March 16, Alibaba announced it planned to launch its IPO in the U.S.

Alibaba's IPO will create a number of millionaires as many of its staff have shares.

"There will be a special department to help you deal with your stake," said Ma in the email.

"I remind you to deal properly with your fortune, take care of your family and donate to society at the same time," he said.