What is the purpose of your e-mail? If you are responding to their request for an interview, I would just reply with whatever information they requested. You can start off with Good morning/Good afternoon and then go on to say something to the effect “I received your email regarding setting up and interview” or whatever. This is not an essay. Just a quick response. Just make sure it is grammatical and no typos. Do not respond in the text speak that so many high schoolers use these days.
Whey I send an email, I just want an acknowledgement that you got it and a response to whatever it is I asked.
Good luck.