U.S. Copyright Office - Visual Art Works Registration

The idea of copyrighting something. the "poor man's copyright" was a certified letter sealed with the contents mail to self and never opened. Well this would work, but in the digital age would emailing your ideas and content "i.e. your graphics etc" to emails you own. so say my handy graphic of don't dis-my-ability if i emailed it to my multiple email addresses and never opened it, would a court case allow me to suppona msn or yahoo or gmail to verify that the emails were never opened. so would that allow me to verify that i had copy rifght to them. that i had created them... i thinks so.