Microsoft is the first largest e-mail service, with 283 million users
Yahoo is the second largest e-mail service, with 274 million users
Gmail is the third-largest e-mail service, with 113 million worldwide users as of September according to comScore.
Google announced Tuesday it is adding video and audio chat to its free e-mail service, joining Microsoft and Yahoo in a race to make communication on the Web a more social experience.
Both Microsoft and Yahoo offer video with their instant messaging services, but have not integrated it into e-mail.
Last month, Yahoo announced it was providing programmers the software instructions they need to write applications that can extend the features of Yahoo mail. Ash Patel, executive vice president of the audience product division, said the goal was to help hundreds of millions of users “communicate better and get more done.”
Microsoft has also been upgrading its communication platform, known as Windows Live