The QB Pro Plus 2023 desktop support could never fix the issue, nor could the Level 3 support with the Office of the President. However, the Level 3 tech did try hard and spent over 8 hours on the issue. Contacting Microsoft was a complete waist of time. Their techs had no clue what to do. Our problem is on a Windows 11 desktop PC that uses Outlook 365. I discovered a work around that works for us in the meantime, but has its drawbacks. We are able to create invoices and estimates in QB Pro Plus, but Outlook must be closed. When the invoice or estimate is completed, we can still open an Outlook email window and apply attachments. When ready, we press SEND, but the email goes away and does not send out. At the end of the ship, the invoice clerk opens Outlook and all the invoices and estimates created during the shift are sent out at the same time. This resolves sending invoices within QB Pro Plus, but it eliminates the clerk from receiving emails throughout the shift. Now, the clerk opens Outlook at the beginning of the shift every day, reads the emails, then closes to work on invoices. As advanced as Microsoft and Quickbooks are, they still cannot figure out this issue. We could go back to Windows 10 and the problem would be resolved, except that Windows 10 versions are slowly moving toward not being supported by Microsoft. It is a plus that I have a lot of IT experience, but frustrating that I know more about it than QB or Microsoft.