Hello there, @paramountwatersa. I'm here to help you email your customers in one go in QuickBooks Online (QBO).
In QBO, you can easily email your customer by batch. I'd be glad to guide you on how:
Navigate to the Sales menu and select Customers.
Then, select all the customers you want to send an email.
Next, click the Batch Actions button.
Click the Email option.
After that, choose your email provider and input the information you need to send to your customer.
You can also email your customer's sales forms by batch in QBO. Here's how:
Go to the Bookkeeping menu and select Transactions.
Then, choose All Sales.
From there, check the boxes for the sales forms you want to email. You can also select the Filter menu to filter by transaction by Type, Status, Date, or Customer.
Next, in the Batch actions menu,click Send transactions.