If you first contact someone via email, then split up the email in short sweet direct segments. Keep it short, no dissertations or long intros of why you are contacting them. You can send details after you have a reply and an ok to provide additional information. I can not tell you how many times I receive an introduction email with an immediate sales pitch or lets meet for coffee before ever speaking with them to see if I am even interested or available.
One of the thing that I do is for each question that you may have in an email, put on a separate line. This should catch the readers attention as to address each question and when they answer it, the response in not buried in the email.
And keep that first email friendly, sincere and short.