Edit in JSFiddle

var emails = $("input[type=email]"),
    total = emails.length;

$("#add").click(function(){
    var div = $("<div></div>"),
        label = $("<label></label>"),
        email = $("<input type = email />");
    
    label.html("Email " + (++total) + ":");
    div.append(label, " " , email);
    $("section").append(div);
    emails = $("input[type=email]");
    email.focus();
    if (total == 5) this.disabled = true;
});

$("#fin").click(function(){
    var valores = [];
    for (i = 0; i < total; i++)
        valores.push(emails[i].value);
  
    if (valores.length) $("p").html(valores.join(", "));
});

<section>
    <div>
        <label>Email 1:</label>
        <input type = "email" autofocus />    
    </div>
</section>
    
<button id = "add">Añadir otro</button>
<button id = "fin">Clic</button>
<p></p>