I signed up for a free RocketMail email account from Yahoo today to use as a test email account. Yahoo offers unlimited storage for the email account. RocketMail was acquired by Yahoo! and relaunched by as Yahoo! Mail in 1997.
John Kremer, a Yahoo! Mail vice president, provides some history on how Yahoo's email account storage capacity has grown over the years. He mentions that when Yahoo! Mail launched in 1997, users got a whopping 4 megabytes (MB) of storage for their email.