Implementation of Domain Keys in Rails

Hi All,

I am looking for implementing domain keys for authenticating outgoing mails through my rails application to prevent the mails going in spams.

I am using SMTP for sending mails using Action Mailer through my application.

Do any one know how to implement in rails or can provide any source or link or it ?

Also does this implementation is platform independent (Does it work same in Windows and Linux)??

Thanks in advance.