Hi,
PDT Id for Site1-PayPalStandardProductionPDTId is not the same thing as merchant id. You have to go into your paypal account under Website Payment Preferences and you have to enable PDT and you have to use the pdt identity token
You should alsonot override these like this:
<add key="Site1-ConfirmationEmailPlainTextTemplate" value="en-US-DefaultOrderConfirmationPlainTextEmailTemplate.config"/>
<add key="Site1-ConfirmationEmailSubjectTemplate" value="en-US-DefaultOrderConfirmationEmailSubjectTemplate.config"/>
<add key="Site1-OrderReceivedEmailPlainTextTemplate" value="en-US-DefaultOrderReceivedPlainTextEmailTemplate.config"/>
<add key="Site1-OrderReceivedEmailSubjectTemplate" value="en-US-DefaultOrderReceivedEmailSubjectTemplate.config"/>
none of those should have the en-US- in the value, though that is the name of the files on disk, it should not be specific in the value, instead it should be like this:
<add key="Site1-ConfirmationEmailPlainTextTemplate" value="DefaultOrderConfirmationPlainTextEmailTemplate.config"/>
<add key="Site1-ConfirmationEmailSubjectTemplate" value="DefaultOrderConfirmationEmailSubjectTemplate.config"/>
<add key="Site1-OrderReceivedEmailPlainTextTemplate" value="DefaultOrderReceivedPlainTextEmailTemplate.config"/>
<add key="Site1-OrderReceivedEmailSubjectTemplate" value="DefaultOrderReceivedEmailSubjectTemplate.config"/>
Hope it helps,
Joe