I am bit confused as to why you ask me to check our sales transaction:

"You may also want to view all your sales transactions. You can go to the Sales menu and select All Sales. This will give you a great view of the status of sales transactions, open invoices, and paid invoices."

everyone in here is talking about a specific issue. What I found out that all the emails that were sent by my team last night were received by clients but it showed as it was bounced at our end and also we did not receive it  because we always cc or bcc all invoices sent to our own email address as well. I am baffled that a company as large as QB is taking this long to fix this issue. Someone needs to reach out to us and not us trying to find solutions and reach out to you!! This is ridiculous.