Answer: Hotmail

Hotmail was originally founded in 1996 and launched on July 4th, Independence Day in the U.S., to symbolize the way it broke users free from ISP-supplied email addresses. Not only did Hotmail break you free from depending on your ISP for email service, but it was also one of the first web-based email services (paving the way for webmail along with RocketMail, which would later become Yahoo! Mail).

The very name of the service was, in fact, a direct nod to the new emerging platform. In the early days, Hotmail was stylized as HoTMaiL—with the capitalized letters forming the acronym HTML—a nod to the HyperText Markup Language that made the World Wide Web and web-based email possible.

Later, post Microsoft purchase, Hotmail retained its name for a period of time—first as MSN Hotmail, then as Windows Live Hotmail—but now Hotmail exists only in the addresses of veteran users as Microsoft has transitioned the service completely over to Outlook.com.