Just becuase Rasoolallah(sawaw) did not go to school does not neccassarily make him illiterate.
Actually it proves his wisdom was in fact divine in itself and that he was educated by Allah himself without any tutor, therefore there could be no"human" error in his work.
Furthermore Rasollallah actually wrote letters inviting many of the monarchs and political figureheads of that era to convert, ask yourself if Rasoolallah was illiterate how could he have written letters to them?
Secondly if you think someonel else wrote them for him 
why was Rasoolallah so angry towards the likes of Khusro Parvez (Chosroes/Kyros) and felt personally agreived upon hearing his message hade been torn apart 
Rasoolallah would not have been so angry if the letter were not written by him would he? (Besides that fact could have been covered up by another writter, but if Rasoolallah had written it himself then he would have been bound to ask what happened to the letter, makes sense, naturally.)
Therefore although Rasoolallah did not go to school it would be wrong to label him illiterate, there is a distinct and subtle difference my fellows, between illiterate and divenely taught.
By labeling our nabi illiterate you seem to suggest he had a weakness!
No this is not so, Chingiz Khan was illiterate, Aesop was illiterate, Abu Jahil was ignorant as well as illiterate…
But the difference between these mere mortals and Rasoolallah is that our beloved Nabi was divinely taught,
To label him illiterate is an insult in plain and simple terms,
He was not.
In conclusion one can only say that Rasoolallah was divinely granted an education which no mere mortal can attain this side of sidratul muntaha.
No University,College or any Educational institution can compare with the knowledgde of the seven skies and no diploma is a match for divine granted wisdom.
How else could Islam lay claim to be the faith of miracles, for it’s very founders were divinely guided and as long as there is but one Muslimwho reads the divine rules of the koran, Islam will rule.
