invalid css

The mailhandler.css file contains verbal names of colors for text and does not validate with w3c validator. Changing to the hexadecimal equivalents reolves this issue:

div.email div.email {
  font-size: 0.95em;
  color: #00008B;
}

div.email div.email div.email {
  font-size: 1em;
  color: #006400;
}

div.email div.email div.email div.email {
  color: #8B0000;
}

div.email div.email div.email div.email div.email {
  color: #008B8B;
}