My customers can not view emailed invoice on their mobile device. is this normal? is there a setting i can update?

Let's help your customers view their invoices, psieczkiewicz68,

There is no option in QuickBooks Online that can cause your customer not to be able to view the invoices. I'd recommend asking your customers to do the following troubleshooting steps:

1. Update their email provider app.
2. Access their email through a mobile browser.
3. Make sure they turn off the pop-up blockers. This might also prevent them from viewing images or details of the invoices.
4. When viewing the email message, they might have the option like Display Images.

If they still can't view the invoices, I'd recommend reporting this to our Customer Care Team. They can further investigate this matter:

1. Click Help in the upper-right corner and select Contact Us.
2. Enter the details of your banking concern and select Let's talk.
3. Select how you want to reach them (phone or chat).
4. Enter the needed information to complete your request.

Meanwhile, you can change how your customers can view the sent invoices. You can follow these steps:

1. Click the Gear icon in the upper-right corner and select Account and Settings.
2. Select the Sales tab and go to the Online delivery section.
3. We recommend setting it to Online invoice.
4. Click Save and Done.

If your customers encounter a specific error message or if you have additional questions, please let us know. We'll get to the bottom of this.