It's not quite what you want, but it's possible using modern javascript to create an EML file on the client and stream that to the user's file system, which should open a rich email containing HTML in their mail program, such as Outlook:
https://stackoverflow.com/a/27971771/8595398
Here's a jsfiddle of an email containing images and tables: https://jsfiddle.net/seanodotcom/yd1n8Lfh/
HTML
<!-- https://jsfiddle.net/seanodotcom/yd1n8Lfh -->
<textarea id="textbox" style="width: 300px; height: 600px;">
To: User <[email protected]>
Subject: Subject
X-Unsent: 1
Content-Type: text/html
<html>
<head>
<style>
body, html, table {
font-family: Calibri, Arial, sans-serif;
}
.pastdue { color: crimson; }
table {
border: 1px solid silver;
padding: 6px;
}
thead {
text-align: center;
font-size: 1.2em;
color: navy;
background-color: silver;
font-weight: bold;
}
tbody td {
text-align: center;
}
</style>
</head>
<body>
<table width=100%>
<tr>
<td><img src="http://www.laurell.com/images/logo/laurell_logo_storefront.jpg" width="200" height="57" alt=""></td>
<td align="right"><h1><span class="pastdue">PAST DUE</span> INVOICE</h1></td>
</tr>
</table>
<table width=100%>
<thead>
<th>Invoice #</th>
<th>Days Overdue</th>
<th>Amount Owed</th>
</thead>
<tbody>
<tr>
<td>OU812</td>
<td>9</td>
<td>$4395.00</td>
</tr>
<tr>
<td>OU812</td>
<td>9</td>
<td>$4395.00</td>
</tr>
<tr>
<td>OU812</td>
<td>9</td>
<td>$4395.00</td>
</tr>
</tbody>
</table>
</body>
</html>
</textarea> <br>
<button id="create">Create file</button><br><br>
<a download="message.eml" id="downloadlink" style="display: none">Download</a>
Javascript
(function () {
var textFile = null,
makeTextFile = function (text) {
var data = new Blob([text], {type: 'text/plain'});
if (textFile !== null) {
window.URL.revokeObjectURL(textFile);
}
textFile = window.URL.createObjectURL(data);
return textFile;
};
var create = document.getElementById('create'),
textbox = document.getElementById('textbox');
create.addEventListener('click', function () {
var link = document.getElementById('downloadlink');
link.href = makeTextFile(textbox.value);
link.style.display = 'block';
}, false);
})();