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

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

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.