HTML Editor delete and modify my code when I insert my HTML Email template

HTML Editor delete and modify my code when I insert my HTML Email template

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns:v="urn:schemas-microsoft-com:vml">
<head>
<title>LoanLogics</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<style type="text/css">
.ExternalClass * {
    line-height: 100%;
}
</style>
</head>
<body style="margin: 0; padding: 0; width: 100% !important;">
    <table width="100%" cellpadding="0" cellspacing="0" border="0">
....

1)When I insert this code to html editor, the html was cut off.

<td align="left" valign="top"
                                                                            style="font-size: 0; line-height: 100%;"><a
                                                                            href="mailto:${User.Email}?subject=Schedule my LoanLogics LoanDecisions&trade; demo&body=I would like to schedule a LoanLogics LoanDecisions&trade; demo."><img
                                                                                src="http://www.loanlogics.com/images/email/btn_product_intro.png"
                                                                                style="border: none; width: 225px; height: 25px;"
                                                                                alt="Product Introduction" width="225" height="25" /></a>
                                                                        </td>
2) The mailto link generate error and I cannot click at all