What do you think about this famous letter that was sent from Prophet Muhammad to the Christians?

Sorry haters, you don't get to use "it's a hoax because he was illiterate". The letter was dictated.

Prophet Muhammad’s (saws) Message to the Monks of St. Catherine’s Monastery

”This is a message written by Muhammad ibn Abdullah, as a covenant to those who adopt Christianity, far and near, we are behind them. Verily, I defend them by myself, the servants, the helpers, and my followers, because Christians are my citizens; and by Allah! I hold out against anything that displeases them. No compulsion is to be on them. Neither are their judges to be changed from their jobs, nor their monks from their monasteries. No one is to destroy a house of their religion, to damage it, or to carry anything from it to the Muslims' houses. Should anyone take any of these, he would spoil God's covenant and disobey His Prophet. Verily, they (Christians) are my allies and have my secure charter against all that they hate. No one is to force them to travel or to oblige them to fight. The Muslims are to fight for them. If a female Christian is married to a Muslim, this is not to take place without her own wish. She is not to be prevented from going to her church to pray. Their churches are to be respected. They are neither to be prevented from repairing them nor the sacredness of their covenants. No one of the nation is to disobey this covenant till the Day of Judgment and the end of the world.”