how do I get the employee email associated with a PO?

HI, 
I am trying to get the employee’s email from a PO in Report Designer. 
If I try & do a join from the PO to the EPEmployee table & then from the EPEmployee table to the contact table (like the employee PL, EP2030PL)  

I get a message that the EPEmployee.DefContactID cannot be bound. 
I have tried doing a join from POOrder to Contact using the EmployeeID to BAccountID & to ContactID but I cannot get the email address. 

Any assistance would be appreciated!
Thanks in advance!
Bill