Many Thanks Nicolas,
I checked the email history and discovered the vendor was getting no emails from HikaShop as I hadn't configured it correctly.
The emails he was getting were from Paypal.
The vendor, under the old system, received, via Paypal, a detailed email stating what was ordered and client details. They still receive an email from Paypal now that we switched to HikaShop, but much less details. I do believe the issue is now resolved, but am curious as to why PayPal advice email has changed - any ideas ?
Kind Regards. M