Yes, there's a way to see what invoices were previously emailed to customers, @July2003.
You can run either the Transaction List by Customer report or the Open Invoices report, making sure to include the Sent column.
Here's how:
- Go to Reports, then select Standard reports.
- In the report name box, enter either Transaction List by Customer or Open Invoices.
- Filter the Report period.
- Click the Columns icon and check the box next to Sent.
- Use the Filter icon to narrow down your data by Transaction type.

Once done, QuickBooks will automatically add a Sent column to the report, allowing you to track emailed invoices.
Lastly, if you're looking to save modifications to the above report, check out this article: Save a customized report.
Should you have further questions about managing emailed invoices in QuickBooks, don't hesitate to leave us a comment here in the Community.