The email upgrade is supposed to make Yahoo's inbox twice as fast. It will also enable users to send the short messages known as 'tweets' directly to their Twitter accounts from the mail service.
"As I"ve learned more about the people and products that make Yahoo! great, I"ve grown even more positive that our future will be a bright one. Our products continue to evolve and at the heart of that evolution is our commitment to bringing personal meaning to the Web for everyone," said Blake Irving, EVP and Chief Product Officer at Yahoo.
"In short, that means helping you and the other 600 million people on Yahoo! cut through the vastness of online data by providing the experiences that are most important to you, whether that"s instantly finding the content you are searching for or connecting you with family and friends," he added.