Already implemented, so your suggestion is invalid (marking thread accordingly). There is a template for ecards defined in include/themes.inc.php (don't edit that file!) that you can override by adding the corresponding section// HTML template for e-cards
$template_ecard = <<<EOT
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html dir="{LANG_DIR}">
<head>
<meta http-equiv="content-type" content="text/html; charset={CHARSET}" />
<title>{TITLE}</title>
</head>
<body bgcolor="#FFFFFF" text="#0F5475" link="#0F5475" vlink="#0F5475" alink="#0F5475">
<br />
<p align="center"><a href="{VIEW_ECARD_TGT}"><b>{VIEW_ECARD_LNK}</b></a></p>
<table border="0" cellspacing="0" cellpadding="1" align="center">
<tr>
<td bgcolor="#000000">
<table border="0" cellspacing="0" cellpadding="10" bgcolor="#ffffff">
<tr>
<td valign="top">
<a href="{VIEW_MORE_TGT}displayimage.php?pos=-{PID}">
<img src="{PIC_URL}" border="1" alt="" /></a>
<br />
<div align="center">
<h2>{PIC_TITLE}</h2>
</div>
</td>
<td valign="top" width="300">
<div align="right"><img src="{URL_PREFIX}images/stamp.gif" border="0" alt="" /></div>
<br />
<b><font face="arial" color="#000000" size="4">{GREETINGS}</font></b>
<br />
<br />
<font face="arial" color="#000000" size="2">{MESSAGE}</font>
<br />
<br />
<font face="arial" color="#000000" size="2">{SENDER_NAME}</font>
(<a href="mailto:{SENDER_EMAIL}"><font face="arial" color="#000000" size="2">{SENDER_EMAIL}</font></a>)
</td>
</tr>
<tr>
<td colspan="2">
{PIC_CAPTION}
</td>
</tr>
</table>
</td>
</tr>
</table>
<p align="center"><a href="{VIEW_MORE_TGT}"><b>{VIEW_MORE_LNK}</b></a></p>
</body>
</html>
EOT;
// plain-text template for e-cards (as fallback for clients that can't display html-formatted mails)
$template_ecard_plaintext = <<<EOT
{TITLE}
=========================================
{VIEW_ECARD_LNK_PLAINTEXT}:
{VIEW_ECARD_TGT}
{GREETINGS}
{PLAINTEXT_MESSAGE}
{SENDER_NAME} ({SENDER_EMAIL})
-----------------------------------------
{VIEW_MORE_LNK}:
{VIEW_MORE_TGT}
EOT;
from themes/sample/theme.php into a new line before ?>
of the file themes/yourtheme/theme.php and then modifying as you see fit.
In the future, please make sure to only request features that really don't exist already.