Yahoomail is the combination of two words that make up a popular e-mail application known as Yahoo! Mail. Yahoo! Mail is Yahoo!'s web-based email service that was first launched on October 8, 1997 to better serve the rising number of Internet users and to compete with the then-very popular web-based email service Hotmail which started a year earlier in 1996.
Yahoo! Mail began the process of updating its then-outdated interface when Google launched its own web-based email service Gmail in 2004. While considered a bit late, Yahoo! unveiled a new Ajax version of its email service in mid-2007, powered by its Zimbra software, to compete with the much faster (in terms of page loading times) and more contemporary designed Gmail.
As of 2007, Yahoo! Mail holds the top market share among the major web-based email services (also including AOL among the aforementioned Gmail and Hotmail).