code: public void addHeader(String name, String value)
      {
          if ((name == null) || name.equals(""))
              throw new IllegalArgumentException("Illegal MimeHeader name");
  
          int pos = headers.size();
  
          for(int i = pos - 1 ; i >= 0; i--) {
              MimeHeader hdr = (MimeHeader) headers.elementAt(i);
              if (hdr.getName().equalsIgnoreCase(name)) {
                  headers.insertElementAt(new MimeHeader(name, value),
                                          i+1);
                  return;
              }
          }
          headers.addElement(new MimeHeader(name, value));
      }
docs: Adds a <code>MimeHeader</code> object with the specified name and value
  to this <code>MimeHeaders</code> object's list of headers.
  <P>
  Note that RFC822 headers can contain only US-ASCII characters.
  
  @param   name a <code>String</code> with the name of the header to
  be added
  @param   value a <code>String</code> with the value of the header to
  be added
  
  @exception IllegalArgumentException if there was a problem in the
  mime header name or value being added