Hello there, @westcoastnursery.

Removing the customers that you don't want to send certain emails is easy. I'd be happy to share the steps on how to do this.

You can exclude the customers that you don't want to be included in the list before exporting them in Excel.

Here's how:

1. On the left panel, click Reports.
2. Look for the Customer Contact List report.
3. Click the Customize button located in the upper right-hand corner. 
4. Refer to the Filter tab.
5. Put a check-mark on Customer and select the customers that you wanted to send an email. 
6. Hit on Run report.

After that, you can now export the report to Excel: 

For more tips about customizing reports in QuickBooks Online, you can always utilize this link: Learn how to get the most out of your financial reports.

If there's anything else that I can assist you with, let me know. I'll be right here for you. Have a good one!