I try to load simple file photos taken with my phone and it says they are too large.
Frogpatch, change the "settings" on your I-phone, .... either the "size" of the picture you are taking .... or the size of the picture you are transmitting.
A friend was sending me pictures that were like
36" by 24" (inches) and up to 2 megabytes in size.
I don't own an I-phone so I can't tell you how to do it.