There is zero chance that we can communicate anything at those timespans. As I already wrote we have trouble to tell what happened 4000 years ago (how were the Pyramids build exactly?) and that is just a blink of an eye when compared to a million years.
Ancient Egypt was a super advanced civilization continuously existing for 4000 years! Yet shortly after the decline nobody could read Hieroglyphs anymore.
We don't know what the future holds. Lets say in 50 years a low intensity Gamma Ray Burst hits earth and destroys all digital information but fries only half of all living creatures. The survivors dig trough the trash of the past to get to the rare earth metals they need to rebuild their civilization and find this really neat bunker with those funny signs...
