Can I check the e-mail sent history of Estimates and Invoices? If so, how can I check it?

I've got the steps you need to check the sent e-mail history of estimates and invoices in QuickBooks Online, rachel-kim-netki.

You can pull up and customise the Transactions List by Customer report to show all the information you need.

Here's how:

1. Click Reports in the left panel and search for Transaction List by Customer report.
   
2. On the report screen, click Customise.
   
3. Go to the Rows/Columns section and tap Change columns.
   
4. Scroll down and select Sent and Delivery Address.
5. Hit Run report.
   
6. You'll see the corresponding e-mail for each transaction.
   

To get more ideas on how to customise and utilise your reports in QuickBooks Online, you can visit the following article: Customise reports in QuickBooks Online. Also, this will provide you a link on how to manage and share your custom reports.

You can always get back to me if you need further assistance or have any other QuickBooks concerns. 'll be more than happy to check on them for you, and I'm here to help you at any time.