Is there a problem with invoices sending currently?

I've got into the habit of CC'ing myself and my business partner to ensure the invoice has gone. Sent one at 2.09 pm UK time, Quickbooks dashboard says the invoice has been sent, but my lack of a CC copy makes me think otherwise. Not the first time this has happened either.

Quickbooks / Intuit - a response please?

Yes there's a major problem been going on since January. See this thread

https://quickbooks.intuit.com/learn-support/en-uk/transactions/my-emailed-invoices-are-not-being-received-by-my-customers/00/794417