SPF Sending email from Iphone

Hey there, hoping some guru here might be able to help me out.

So I'm new to the idea of SPFs, never had to use them before, but I certainly do need to now (tons of spoofed emails)

So I activated my SPF through my Cpanel. Only thing now is that my iPhone seems to be having trouble sending emails when not on the WiFi. Makes sense, I suppose my cellular network has a different IP, right?

So how do I allow my iPhone to send emails? Is there some sort of cellular IP I need to authorize?

Any help would me awesome. Thanks all!.