mails accessed with OAuth

it looks like Yahoo actually implemented OAuth several days before Gmail got around to it.

OAuth access to your email means that you can give simple, one-click authorization to external applications to have full access to your emails. This also means you can have seemless access to the information in your email account, from the contents of the emails themselves to your contact list, on other websites.

http://www.readwriteweb.com/archives/yahoo_mail_gets_unrestricted_api_access_with_oauth.php