I think we have all been very patient, the only time QBO provides generic feedback with no date of a solution, is when this thread is revived.

I have not seen one email from QB sent to their clients or a notification within QBO that says you are looking into this issue, so it seems it is only being addressed here, which boggles my brain.

This month, more than 80% of the invoices were undelivered. 

I can't stress enough how much extra time this is consuming as well as frustrated clients who now think after years and years that suddenly we not doing our job properly but the problem is with QBO itself.

We need more information from QBO on what is being done to resolve the blacklisting of your domain when sent directly to clients and what the ETA is of a solution.