Rocketmail was one of the first free, web-based email clients on the market and was produced by a company known as Four11. In the late 1990s, Four11 was acquired by Yahoo, and Rocketmail became Yahoo Mail until fairly recently (2008), Yahoo resurrected the Rocketmail name and now lets its users choose either a Yahoo mail address or Rocketmail address. Creating your own Rocketmail account is simple and can easily be done in as little as 15 minutes.
Visit the Yahoo Mail webpage under the "Resources" tab and click on "Create Account" on the right-hand side of the page.
Enter your personal information on the screen that comes up and choose a username or user ID for your new account.
Click on the drop-down box next to the username and select "rocketmail.com." Click "Check" to see if your username is available as a Rocketmail account. If it is, agree to the terms and conditions and click submit to open your new account.
Change your username slightly if it is not available as a Rocketmail account and then click "Check" again. Adding numbers or a middle initial to a name often helps.