Windows Live Hotmail, formerly known as MSN Hotmail and commonly referred to simply as Hotmail, is a free webmail service of the Windows Live brand provided by Microsoft.

The Hotmail web-based email service was founded by Jack Smith and Sabeer Bhatia and launched in 1996. Hotmail was one of the first free webmail services. It was subsequently acquired by Microsoft in 1997 for an estimated $400 million, and rebranded as “MSN Hotmail”. The current version, “Windows Live Hotmail” was officially announced on November 1, 2005 as an update to Microsoft’s existing MSN Hotmail service. After a period of beta testing, it was officially released to new and existing users in the Netherlands on November 9, 2006 as a pilot market. The worldwide release was on May 7, 2007, and roll-out to all existing users was completed in October 2007.

Windows Live Hotmail features 5 GB of free storage, patented security measures, Ajax technology, and integration with Windows Live Messenger, Spaces, Calendar and Contacts. It has over 260 million users worldwide and is available in 35 different languages.
Similar to other major webmail services, Hotmail uses Ajax programming techniques and supports the most popular internet browsers (Internet Explorer and Mozilla Firefox). Some of its features include keyboard controls giving the ability to navigate around the page without using the mouse, advanced message search[citation needed] including structured query syntax such as “from:ebay”, message filters, folder-based organization of messages, auto-completion of contact addresses when composing, contact grouping, importing and exporting of contacts as CSV files, rich text formatting, rich text signatures, spam filtering and virus scanning, support for multiple addresses, and different language versions.

Users can choose from two different versions of Hotmail. The “Classic” version keeps the interface and layout based on MSN Hotmail, while using little Ajax technology. The “Full” version employs a more advanced user interface styled on that of Microsoft Outlook, with a reading pane and drag-and-drop capability. All other features are available in both versions.