UTF-8 special character in utl-smtp

Question

Hi, I'm trying to send out an email which has special characters in the body and in the subject like. I have tried all sort of methods to solve my problem. In the code below I have underlined the methods that I have tried. But all of them result in "?????" I'm running on 11g. can you please let me know what I can do to resolve this problem.
CREATE OR REPLACE PROCEDURE PR_SEND_EMAIL
  ( p_from_email_address   VARCHAR2
  , p_to_email_address     VARCHAR2
  , p_smtp_host            VARCHAR2
  , p_subject              VARCHAR2
  , p_message              VARCHAR2
IS
  /*Your query as cursor */
  CURSOR emp_cur IS
    SELECT * FROM a_tre_alert;
  /*UTL_SMTP related varriavles. */
  v_connection_handle  UTL_SMTP.CONNECTION;
  /* This send_header procedure is written in the documentation */
  PROCEDURE send_header(pi_name IN VARCHAR2, pi_header IN VARCHAR2) AS
  BEGIN
    UTL_SMTP.WRITE_DATA(v_connection_handle, pi_name || ': ' || pi_header || UTL_TCP.CRLF);
  END;
BEGIN
  /*UTL_SMTP related coding. */
  v_connection_handle := UTL_SMTP.OPEN_CONNECTION(host => p_smtp_host);
  UTL_SMTP.HELO(v_connection_handle, p_smtp_host);
  UTL_SMTP.MAIL(v_connection_handle, p_from_email_address);
  UTL_SMTP.RCPT(v_connection_handle, p_to_email_address);
  UTL_SMTP.OPEN_DATA(v_connection_handle);
  send_header('From', '"Sender" <' || p_from_email_address || '>');
  send_header('To', '"Recipient" <' || p_to_email_address || '>');
  send_header('Subject', p_subject);
  --MIME header.
  UTL_SMTP.WRITE_DATA(v_connection_handle, 'MIME-Version: 1.0' || UTL_TCP.CRLF);
  UTL_SMTP.WRITE_DATA(v_connection_handle, 'Content-Type: multipart/mixed; ' || UTL_TCP.CRLF);
  UTL_SMTP.WRITE_DATA(v_connection_handle, ' boundary= "' || 'SAUBHIK.SECBOUND' || '"' || UTL_TCP.CRLF);
  UTL_SMTP.WRITE_DATA(v_connection_handle, UTL_TCP.CRLF);
  -- Mail Body
  UTL_SMTP.WRITE_DATA(v_connection_handle, '--' || 'SAUBHIK.SECBOUND' || UTL_TCP.CRLF);
  UTL_SMTP.WRITE_DATA(v_connection_handle, 'Content-Type: text/PLAIN;charset=utf-8' || UTL_TCP.CRLF);
  UTL_SMTP.WRITE_DATA(v_connection_handle, 'Content-Transfer-Encoding: quoted-printable'|| UTL_TCP.CRLF);
-- UTL_SMTP.WRITE_DATA(v_connection_handle, 'Content-Transfer-Encoding:  8bit' || UTL_TCP.crlf);
-- UTL_SMTP.WRITE_RAW_DATA(v_connection_handle, utl_encode.base64_encode(utl_raw.cast_to_raw(p_message))|| UTL_TCP.CRLF);
  UTL_SMTP.write_raw_data(v_connection_handle, UTL_RAW.CAST_TO_RAW(p_message));
  UTL_SMTP.WRITE_DATA(v_connection_handle, UTL_TCP.CRLF);
-- UTL_SMTP.write_raw_data(v_connection_handle, UTL_RAW.cast_to_raw(UTL_TCP.crlf ||p_message));
  --UTL_SMTP.WRITE_DATA(v_connection_handle, ' charset=US-ASCII' || UTL_TCP.CRLF);
  --UTL_SMTP.WRITE_DATA(v_connection_handle, UTL_TCP.CRLF);
-- UTL_SMTP.WRITE_DATA(v_connection_handle, p_message || UTL_TCP.CRLF);
  UTL_SMTP.WRITE_DATA(v_connection_handle, UTL_TCP.CRLF);
  UTL_SMTP.WRITE_DATA(v_connection_handle,'Due Date--Amount--State--ChkSerial--APSerial--AccountCode--FloatAccountتست'|| UTL_TCP.CRLF);
  FOR i IN emp_cur
  LOOP
    UTL_SMTP.WRITE_DATA(v_connection_handle,  i.chequedate || '--' || i.rialamount || '--' || i.state || '--' || i.check_serial || '--' || i.ap_serial || '--' || i.acc_code || '--' || i.facc_code || UTL_TCP.CRLF);
  END LOOP;
  UTL_SMTP.WRITE_DATA(v_connection_handle, UTL_TCP.CRLF);
  -- Close Email
  UTL_SMTP.WRITE_DATA(v_connection_handle, '--' || 'SAUBHIK.SECBOUND' || '--' || UTL_TCP.CRLF);
  UTL_SMTP.WRITE_DATA(v_connection_handle, UTL_TCP.CRLF || '.' || UTL_TCP.CRLF);
  UTL_SMTP.CLOSE_DATA(v_connection_handle);
  UTL_SMTP.QUIT(v_connection_handle);
EXCEPTION
  WHEN OTHERS THEN
    UTL_SMTP.QUIT(v_connection_handle);
    RAISE;
END;
CREATE OR REPLACE PUBLIC SYNONYM PR_SEND_EMAIL FOR PR_SEND_EMAIL;
BEGIN
  PR_SEND_EMAIL ( p_from_email_address => '[email protected]'
                    , p_to_email_address   => '[email protected]'
                    , p_smtp_host          => 'xx.xxx.xx.x'
                    , p_subject            => 'SPECIAL CHAR'
                    , p_message            => 'SPECAIL CHAR'
EXCEPTION WHEN OTHERS
   THEN DBMS_OUTPUT.PUT_LINE('ERROR in Procedure PR_SEND_EMAIL - ' || SQLERRM);
        RAISE;
END;

Answer 1

Is using a trigger a wise idea???