HTML

email and button bootstrap

$(document).ready(function() {
  $('#mailbutton').click(function(event) {
    window.location = "mailto:example@example.com";
  });
});

email and button bootstrap

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet" />
<a href="#" id="mailbutton" class="btn btn-primary">Send us a mail!</a>