function sendMail() {
var link = "mailto:me@example.com"
+ "?cc=myCCaddress@example.com"
+ "&subject=" + encodeURIComponent("This is my subject")
+ "&body=" + encodeURIComponent(document.getElementById('myText').value)
;
window.location.href = link;
}
<textarea id="myText">
Lorem ipsum...
</textarea>
<button onclick="sendMail(); return false">Send</button>