It's my priority to help you sort it out, gemgirl

We can check the Recurring invoice you have created to verify if the email address was entered in that transaction. 

Here's how: 

1. Click the Gear icon. 
2. Choose Recurring Transactions. 
3. Open the Recurring invoice, and check under Email if the email enter. 
4. Tap Save template if modify made. 

Even though you mark checked the Email me a copy in the setting, there is a limitation on sending the Sales form in QuickBooks Online.    

You might want to check out these helpful articles for your reference:  

•  Edit a recurring template 

• How to create a recurring invoice and manage recurring transactions  

In case you have a recurring transaction that doesn't send automatically, you can view the article provided. It rolls up a few steps you can try whenever you experience a situation that a recurring template doesn't automatically send out an email.

Drop me a comment below if you have any other questions. I'll get back to you as soon as possible. Have a great day!