Definition: Compose a new way to ask the same question. The new question must be asking the exact same thing as the original question does. Without any other information, you should be able to tell that the original question and the new question are the same. Preserve bracketed phrases in your new question. You can change the rest of the question provided the above requirements are satisfied. The new question must have a natural, fluent formulation, as if it were composed by a native English speaker. You will be given three pieces of information to help you create better questions. Those are: "Answer": the answer to the question, e.g., "Honolulu". "Answer Type": the type of the answer, e.g., "Location". "Auxiliary Information" is a detailed description of some concepts mentioned in the question, if any.
Input: original question: how many Protocol does the API of [Yahoo! Mail] have?
answer: 2
answer type: Protocol.
auxiliary information: Yahoo Mail is a free email service offered by the American company Yahoo!. It was launched in 1997, and, according to comScore, Yahoo Mail was the third-largest web-based email service with 281 million users as of December 2011. As many as three web interfaces were available at any given date. The traditional "Yahoo Mail Classic" preserved the availability of their original 1997 interface until July 2013 in North America. A 2005 version included a new Ajax interface, drag-and-drop, improved search, keyboard shortcuts, address auto-completion and tabs. However other features were removed, such as column widths and one click delete-move-to-next. In October 2010, Yahoo released a beta version of Yahoo Mail that included improvements to performance, search and Facebook integration. In May 2011 it became the default interface. Their current Webmail interface was introduced during 2012. Yahoo Mail had unlimited storage from March 27, 2007 until October 8th, 2013. The new design introduced to users from October 2013 was met with heavy criticism of its layout and user ability.

What is the number of protocols the API of [Yahoo! Mail] has?