I agree the Intuit Support responses are laughable.
The number of IP addresses depending on the specific product (aka QB online) and the country should not be that huge (talking to you Intuit).
Google and Yahoo are getting more stringent. It's baffling considering the huge user base of Quickbooks Online there isn't clearly published (and compliant) SPF and DKIM record settings accessible from within your account settings.
Email deliverability is only going to get worse if they don't do this.
Your 2024 guide to Google and Yahoo’s new requirements for email senders | Postmark (postmarkapp.com...
