PO Approval to External Mail

Dear Guru

My Requirement is that when ever PO has to been Approved from External Mail like Microsoft outlook

When my PO is created it trigger Workflow and through Mail Notification it will send to the SAP Inbox say that it has to be approved.

In the Same way when a mail goes to Microsoft Outlook, in my mail i should have an option 1. accept or 2. Reject so that i can directly click on it so that it will update in the Back End ECC or when i click  the link it will directly open the SAP Portal UWL List were i can decide to accept or reject.

Can Some body send me the Previous links or how can i do this.

Thanks and Regards

Sridhar