Hello @JK_0322 ,
According to RFC standards, SPF should be verified on the ‘return path domain’, not the ‘from domain’. If you are sending over our shared network then we have configured SPF on your ‘return path domain,’ and if you are sending from a dedicated IP then you have configured it yourself during the IP configration process. That said, Google/Yahoo are likely following RFC best practice and only checking for SPF on the ‘return path domain’ which is why you are passing SPF without configuring it on the ‘from domain’.
The reason we encourage customers to configure SPF on the ‘from domain’ is because we know there are providers who check for it here despite that being against RFC best practice. All of this is to say that as far as Google/Yahoo are concerned you should be good to go.
Hope this helps!