Link PO Confirmation to vendor's email address. Print management.

Hi All, 

I try to set up Print management to have the PO confirmation to link to the vendor's email address.  I have this error below:  

Where do I set up the "To field" address? I have the email address recorded in the Contact tab.  The email address is confirmed as a valid one.

Here is my set up.  Please suggest if I'm missing something