email is not sent to customer after checkout

[the_shop_guy]

I am using latest version of ShopSite with Paypal Express.
When a user shops and checks out at my store, the user or me do not get an email from my store.
After checkout an email is sent from Paypal to the user notifying them about the financial transaction, but they never see an email from my store detailing the product/service they bought.

I looked into this matter and saw that Paypal reviews every transaction that comes to my store's Paypal account (for whatever reason) and after a few days of review it sends another email to me about the success of transaction.
I believe this confuses Shopsite and make it not send an email to the customer or me at all, even when Paypal verifies the transaction.
What is the solution to this problem?

Note, my store's Paypal account is verified and has debit/credit account connected to it.

[Jim]

Check this Kbase solution and see if it applies to your store.
http://support.shopsite.com/KBase/questions/2559
Different email host have implemented the DMARC checking through out the year so this may have come into play later in the year depending on your email host.