Hi there, @RobHere.

Good news! Our back end team has identified a workaround for this unexpected behavior. I'd be glad to share with you the steps. 

To start, let's make sure to create a backup copy of your company file. Then, follow these steps below.

1. Uninstall QuickBooks 2020 then reinstall QuickBooks 2020 R4 using this download link https://tinyurl.com/yx8ado2k
2. Send an email and grant QuickBooks access to use mail.
3. Go to System Preferences, then choose Security and Privacy and select Automation on the left.
4. Under QuickBooks 2020, check Mail.
5. Close Preferences on QuickBooks 2020, then re-update to R5 through Quickbooks.
6. Go to Check for QuickBooks Updates.

If you are still experiencing this issue, refer to this article: Fix a Scripting Permission Problem when you email an invoice.

Thank you for being patient with us while we worked to resolve this issue for you.