". it will send to all other psu.edu adresses but no others.... "
I can't tell since I don't know your SMTP server settings. For instance I did set up a business internal use only SMTP server that ONLY allowed email to internal company addresses. Its possible your SMTP server is doing this and no error on your part. Check with your ISP what the SMTP should be.
Does anyone know why my outlook would be telling me that the reciepient was rejected... it will send to all other psu.edu adresses but no others....