Yahoo! launched RocketMail brand on 19th June 2008, more than a decade after acquiring it.
Yahoo! Mail and Four 11’s RocketMail were the first free web-based email services. In 1997, Yahoo! acquired Four 11 and, thus, the RocketMail brand. RocketMail users were shifted to Yahoo! Mail.
Only in 2008, did they let new users create email addresses on the rocketmail.com domain name.