The Origins of Authorship in the New Testament

I don't get too far enough about matters concerning authorship. I mean, from, in most of his letters, Paul is with other people and he sends greetings to them. His letters would have been the product of discussion about the contours of a certain problem or what they wanted to say. There are people that took down, uh, dictation, Paul did not quote unquote write his letters at the end of Romans.