I'm on your side here, IT-IN-A-BOX.

As a QuickBooks user who wants to keep your data secure, everything you've shared in this thread makes total sense.

I understand that the option to set up your email address could help your customers distinguish you from scammers. While this is unavailable, I'd recommend including a note in the email.

Here's how:

1. Open the invoice that you'd like to send.
2. Verify the details.
3. Select Save and send.
4. On the Send Email page, add your note.
5. Once done, click on Send and close.

For more details about personalizing your email, please see this article: Customize Invoices, Estimates, and Sales Receipts.

Additionally, I've added an article that'll help you gently remind your customers about invoice due dates: Send Reminders Automatically or Manually.

I appreciate your understanding on this matter. Please know that you're security is our top priority.