There are few a reasons why your invoice ends up in the junk folder, @Vishal1. I'll share some of them as I provide a workaround for you.
The email domain of your customer is likely restricting @intuit.com, which is why some emails from QuickBooks Online were flagged as spam. In this case, you'll want to advise them to select This is not spam or Not Junk when they find your email in their spam folder.
Additionally, you'll want to inform them to add quickbooks@notification.intuit.com to their contacts or send a sample email to do not reply@intuit.com. This makes it easier for their email provider to identify the @intuit domain as a reputable website.
Feel free to read these resources to learn more about QuickBooks Online email server hostnames and IP addresses:
I’ve added this reference to help you personalize and add specific data to your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online.
Once everything is settled, feel free to read this guide about receiving invoice payments in the program: Record invoice payments in QuickBooks Online.
Drop a post anytime if you still have questions or concerns with invoices or about the program feature. I'm always here for you. Stay safe.
