Who is underestimating? I agree with ShawnCplus. There is no way that we can understand him if he wants to formulate a question in such imprecise way. My concern, this is not a question related to PHP. Giving that tutorial and you delivering another simplest, what easy is to send an email in PHP and what is a mail server... that may be already known by him.
You could take this with a little sense of humour or not, almost all of us we are programmers in real life, if you want to be get angry or feel depressed is your choice, but listening is an art, as well as respecting diversity of opinions and different points of view.