I'm fed up with the delay in resolving this.  I suspect this is affecting way more people, but that they aren't connecting the issue to the IP addresses.  I googled "quickbooks emails bouncing" and went in circles through solutions that made it seems like the issue was on my end.  I only found this thread because someone linked to it from another question.  185 emails bounced yesterday.  I have clients complaining that they haven't gotten an email in MONTHS.  Why is this not being prioritized?