It is not the experience we want you to have, Oldtimer. Let's take some troubleshooting steps to correct this unusual behavior when emailing your sales forms in QuickBooks Desktop Enterprise.

To address common errors you encounter when using the program, specifically when emailing your invoices, let's utilize the QuickBooks Tool Hub and run a quick repair on your program. I'll guide you through the process.

First, ensure to close QuickBooks for a simultaneous process. Then follow the steps provided below:

1. Download the most recent version (1.6.0.5) of the QuickBooks Tool Hub, then save the file where you can locate it. 
2. Open the file you downloaded (QuickBooksToolHub.exe).
3. Follow the on-screen steps to install and agree to the terms and conditions.
4. Double-click the icon on your Windows desktop to open the tool hub when the installation finishes.

After that, run the Quick Fix my Program. This step will shut down any open background processes QuickBooks uses. It'll run a quick repair on your program.

1. Open the QuickBooks Tool Hub if it's not already open.
2. In the Tool Hub, select Program Problems.
3. Select QuickBooks Program Diagnostic Tool. Let the tool run. It can take up to 20 minutes.
4. When the tool finishes, restart your computer and relaunch QuickBooks.

Once done, email your invoices and recheck if the shaded lines still appear. If the issue persists, I recommend contacting QuickBooks Desktop support. They can help you review what's causing shaded lines to appear on your emailed invoices.

I've also added this article about customizing email templates sent to customers and vendors, supporting a professional appearance in your communications: Creating custom email templates.

I'm always here for you whenever you require further help regarding emailed forms in QuickBooks Desktop. Click the reply button below and type in your query.