I appreciate the prompt response, Felipe.
Currently, adding recipient email addresses when uploading invoices using the Spreadsheet Sync tool in QuickBooks Online is unavailable. The sync tool primarily uploads invoice data, but doesn’t support adding email column for invoice recipients.
As a workaround, you’ll need to ensure the customer's profile includes an email address. This way, the email field will automatically populate when creating invoices. After verifying this information, you can import your invoices using the Spreadsheet Sync tool, and QuickBooks Online (QBO) will link the customer's email address to the respective invoice automatically.
Also, you can still continue uploading your invoices as an Excel, as it includes an email function when mapping your imported invoices.
I’ll be sharing this link that offers guidance in importing and recording your templates in QuickBooks:
If there's anything else we can do to help, feel free to click on the Reply button. I’m here to lend a hand.