Microsoft plan to rename their Hotmail email service, used by millions of people around the world, to Outlook.
It is part of an overhaul to make the service more user-friendly.
The revamped service will have better junk mail filters, sort messages as they arrive and integrate social media in an attempt to compete with Google's rival Gmail.
Microsoft's corporate vice president of Windows Live, Chris Jones, said: "We are giving you the first email service that is connected to Facebook, Twitter, LinkedIn, Google, and soon, Skype, to bring relevant context and communications to your email."
Hotmail was launched by the company in 1996 but has not been updated for eight years.
The Outlook service is being offered as a preview at first and any users who switch to the new system will be able to keep their @hotmail, @msn or @live.com email address.