Today Yahoo! released their API for mail. Developers can now write apps that read, search and write mail messages to/from the Yahoo! Mail service. I’m a big fan of Y! Mail (though I wish that the beta for chat and calendar would hit my account already). I’ve been a premium account holder for about three years now.
Here’s a screencast giving an overview of the new API.
Be sure to also check out these sample applications written to show off the functionality possible with this new API.
This makes me want to code. All of these potential uses of a Yahoo! Mail API are bouncing around in my head.

Go for it! If you need help, feel free to come and join us on the ydn-mail Yahoo! Group.
http://tech.groups.yahoo.com/group/ydn-mail/
Ryan Kennedy
Yahoo! Mail Web Service