Is it possible to send mail using OAuth for GMail

I want to send mail from user gmail account using OAuth to all user contacts.

It's easy to get all contacts of user with google API, but i cant send email to these contacts from user gmail account w开发者_JS百科ithout request his password.

Yes.

The protocol allowing for an application to access IMAP and SMTP using OAuth is based on the Simple Authentication and Security Layer (SASL) and the native IMAP AUTHENTICATE and SMTP AUTH commands.

Since you can use SMTP via OAuth, you can send mail.

http://code.google.com/apis/gmail/oauth/