<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format">
  <xsl:template match="/">
  <xsl:for-each select="//VS">
    <xsl:variable name="curMail" select="Email" />
      <tr bgcolor="#DDECFE">
        <td>Email</td>
        <td>
           <a href="mailto:$curMail">
            <xsl:value-of select="Email" />
          </a>
        </td>
      </tr>
      </xsl:for-each>
</xsl:template>
</xsl:stylesheet>

         <a>           
              <xsl:attribute name="href">
                mailto:<xsl:value-of select="Email"/>
              </xsl:attribute>
            <xsl:value-of select="Email"/>
          </a>