Sending OUTLOOK mail from Workflows

HI ,

Please help me in getting out of this error encountered during a sample workflow thing.

Here is the requirement I need to send a OUTLOOK mail from SAP.If the user accepts the workflow task then mail  need to send a recipient ,stating that he accepthed the request.

Below I designed  that task.

In send Mail step I added the recipent thing as stated below.But I was unable to send mail to OUTLOOK .In this I am not even  getting notification in my SBWP  in SAP INBOX.

How should i send the mail to OUTLOOK from SAP.