The Yahoo Mail Web Service API is a full-featured interface to Yahoo! Mail. With it, you can build applications that display message summary information, parse message contents, manage folders, and even compose and send messages. The Web Service uses OAuth for authentication and access to mailbox contents.
Despite the popularity of micro blogging, instant messaging and social networks, email still plays a huge role in communicating across the internet. This fact is not lost on the big players, who are actively looking for ways to add value to their email services. We have already reported on some changes Google have made to Gmail by implementing the OAuth protocol to make it more open and secure for external access, but it seems that Yahoo beat them to the post, who have also implemented OAuth for their Yahoo Mail API.