Wikipedia article shows a letter that is claimed be sent from Muhammad to the Emperor of Byzantine Empire.
But it doesn't have any information about authenticity of the letter as in if it is actually the real letter sent to the Basileus by the Islamic Prophet.
Is it authentic? Is it accepted as authentic by historians?
After searching the internet for a while, I found this video (Original Letters of Prophet Muhammad) which shows a letter (at 2.19) that seems to be different from the letter shown in the Wikipedia page cited above. The video claims the letter shown in the video is authentic (at 2.35).
Which one is authentic? The one shown in the video or the one shown in the Wikipedia page? Are they both authentic (maybe Muhammad sent both letters)?