Enumeration hdrLines = part.getNonMatchingHeaderLines(ignoreList);
while (hdrLines.hasMoreElements())
los.writeln((String)hdrLines.nextElement());
// The CRLF separator between header and content
los.writeln();
// Finally, the content. Encode if required.
// XXX: May need to account for ESMTP ?
os = MimeUtility.encode(os, part.getEncoding());
part.getDataHandler().writeTo(os);