Hello there, @gpllc.

I appreciate the things you've done to be able to send your invoices. I'd highly recommend contacting our Technical Care Team since you've already performed the initial troubleshooting steps. They have the tools to do a screen-share session and help you send your invoices.

Here's how you can reach them:

1. Go to the Help menu and select QuickBooks Desktop Help.
2. Select Contact Us.
3. Give a brief description of your issue, then select Let's talk.

 You may also want to check the support hours before contacting them to know the best time to call at your convenience.

I've added some articles that are relevant to your concern:

• How to fix "Error: QuickBooks is unable to send your email to Outlook."
• Unable to email transactions or send forms using QuickBooks email service.

Let me know if you have other questions or concerns. I'll be here to back you up. Take care.