Stratfor said in December that its data servers were hacked by the group Anonymous, which has aligned itself with WikiLeaks.
WikiLeaks said on its Web site the e-mails are dated between July 2004 and this end of 2011.
"They reveal the inner workings of a company that fronts as an intelligence publisher, but provides confidential intelligence services to large corporations, such as Bhopal's Dow Chemical Co., Lockheed Martin, Northrop Grumman, Raytheon and government agencies, including the U.S. Department of Homeland Security, the U.S. Marines and the U.S. Defense Intelligence Agency," the Internet whistle-blower said. "The e-mails show Stratfor's web of informers, pay-off structure, payment laundering techniques and psychological methods."
WikiLeaks said among the e-mails was one from Stratfor Chief Executive Officer George Friedman instructing a company analyst how to exploit an Israeli intelligence informant providing information on the medical condition of Venezuelan President Hugo Chavez.
It also said there are more than 4,000 e-mails mentioning WikiLeaks or the organization's founder, Julian Assange.
"The e-mails also expose the revolving door that operates in private intelligence companies in the United States," WikiLeaks said on its Web site. "Government and diplomatic sources from around the world give Stratfor advance knowledge of global politics and events in exchange for money. The global intelligence files exposes how Stratfor has recruited a global network of informants who are paid via Swiss banks accounts and pre-paid credit cards. Stratfor has a mix of covert and overt informants, which includes government employees, embassy staff and journalists around the world.
"The material shows how a private intelligence agency works, and how they target individuals for their corporate and government clients."
WikiLeaks said it has built an investigative partnership with more than 25 media organizations and activists to disseminate information from the millions of e-mails.