You've got my back, support-hospital. I've got options on how to check emails that have been sent out.
With QuickBooks Online, you can run the Transaction List by Customer report and customise it by adding the Sent column to it. Let me show you how:
- Go to the Reports menu.
- Scroll down to the Sales and customers section.
- Choose Transaction List by Customer.
- Click the small Gear icon and ensure the Sent box is marked checked.

- Tap Run report.
Another way is through the Audit log to ensure those transactions were sent out. Please see the steps below:
- Go to the Gear icon.
- Select Audit Log.
- Look for the transaction. If it was sent out, you'll see Emailed under the Event field.
That's it! If you have other questions, do add them in the comment below. I'll be glad to help.