I appreciate you for joining the thread, WowMissy.
I know how important to your business that everything is working. Let me route you to the best support so this can be fixed as soon as possible.
Our engineering team already identified this issue is caused by the most recent Office 365 released update. Reinstalling and updating your outlook to the latest released should fix this. Also, let's ensure that your QuickBooks software is up-to-date. If so, I'd suggest reaching out to our Support Team. They have the tools to do screen sharing and further investigate why it hasn't been fixed yet.
Here's how:
- Go to the Help menu and select QuickBooks Desktop Help.
- Choose Contact Us.
- Enter a brief description of your issue in our Ask a question (or tell us what's wrong) field.
- Click Continue, then select the available options to connect.
Support hours are Monday to Friday from 6 AM to 6 PM PT.
For your reference, you can review this guide here on how to fix this outlook error: Outlook cannot log on when emailing in QuickBooks Desktop.
Reply to this post if you have further questions about emailing invoices. The Community and I will always here to help you 24/7. Have a good day!
