I've just received an email from Gigantic Tickets.

The design caught my eye and viewed the source.

The content of the email i.e. the full HTML file is wrapped in a <script> tag, which is nested in the head of an HTML DOM nodes.

I've never seen this before. What would be the reason for this?

Can't scope the email due to js wrapping but here's what it looks like:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
    <head>
        <meta http-equiv="content-type" content="text/html; charset=utf-8">
        <script type="text/javascript">
            var jsText = '<!DOCTYPE html>' +
'<html><head><meta content="text/html; charset=utf-8" http-equiv="Content-Type"><meta content="text/html; charset=utf-8" http-equiv="Content-Type"><meta name="format-detection" content="date=no"><meta name="format-detection" content="address=no"><meta name="format-detection" content="telephone=no"><link href="http://fonts.googleapis.com/css?family=Roboto:400,700" rel="stylesheet" type="text/css"><title></title><style>' +
'       body {background-color: #dedede;}' +
'       /*@media screen and (max-width: 650px)  and (-webkit-min-device-pixel-ratio: 2) {*/' +
'       @media screen and (max-width: 650px)  {' +
'           body{margin:0px!important; padding:0px!important;}' +
'           .mobile_full_width{float:left!important; width:100%!important;}' +
'           .width_100_percent{width:100%!important;}' +
'           .mobile_full_2col {width:50%!important;}' +
'           .mobile_full_3col {width:33%!important;}' +
'           .hide{display:none !important;}' +
'           .mobile_click {display:block!important; width:100%!important;}' +
'           .mobile_font_xl{font-size:20pt!important;}' +
'           .mobile_font_l{font-size:15pt!important;}' +
'           .mobile_font_m{font-size:12pt!important;}' +
'           .mobile_font_s{font-size:10pt!important;}' +

**etc etc... body content
**
<p style="color:#FFF; font-size:8pt; font-family:Arial, Helvetica, sans-serif; margin:0px; padding:0px;" class="mobile_font_m mobile_font">Gigantic is a trademark of Gigantic Tickets Limited. Registered in the United Kingdom, company number 06044575, VAT number 898361662. Registered office: Gigantic, The Courtyard, 35-37 St Marys Gate, Lace Market, Nottingham, NG1 1PS </p>' +
'                                           </td>' +
'                                       </tr></table></div>' +
'                           </td>' +
'                       </tr></table><!-- End Footer --></div>' +
'                       </td>' +
'                   </tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></body></html>' +
' ';
            //will relplace all template params with provided values
            window.onload = function() {
                var allGets = {};
                var parts = window.location.search.replace(/[?&]+([^=&]+)(=[^&]*)?/gi, function(m,key,value){
                        allGets[key] = (value === undefined) ? true : value.substring(1) });

                getParam = function(key){
                    return allGets[key] === undefined ? '' : allGets[key] ;
                }

                //get all matches
                var matches = jsText.match(/\{\{(.+?)\}\}/gi);

                for(var key = 0; key < matches.length; key++) {
                    jsText = jsText.replace(matches[key], decodeURIComponent(getParam(matches[key].replace(/[{}]/g, ''))));
                }

                document.write(jsText);
            }
        </script>
    </head>
    <body>
    </body>
</html>