THANKYOU.  Registered just to up vote your comment. Found it super odd that articles on SPF were linking to those long list as if they were a workable solution.

It's verging on irresponsible to expect the QuickBooks users to use the domain list for SPF (10 lookup limit kills it) or the IP list which will looses reference and is unmaintainable when QuickBooks add or remove a IP (and they have as old stackoverflow questions show older lists).

They have to expect and understand customers will have other services as well as their own email host in the SPF also. How they have not set up a usable include:_spf.intuit.com reference is mind boggling.