CREATE OR REPLACE PROCEDURE send_mail (p_to        IN VARCHAR2,
                                       p_cc        IN VARCHAR2 DEFAULT NULL,
                                       p_bcc       IN VARCHAR2 DEFAULT NULL,
                                       p_from      IN VARCHAR2,
                                       p_subject   IN VARCHAR2,
                                       p_message   IN VARCHAR2,
                                       p_smtp_host IN VARCHAR2,
                                       p_smtp_port IN NUMBER DEFAULT 25,
                                       p_user_name IN VARCHAR2 DEFAULT NULL,
                                       p_password  IN VARCHAR2 DEFAULT NULL)
AS
  l_mail_conn   UTL_SMTP.connection;
  l_boundary    VARCHAR2(50) := '----=*#abc1234321cba#*=';
  l_step        PLS_INTEGER  := 57;

  PROCEDURE process_recipients(p_mail_conn IN OUT UTL_SMTP.connection,
                               p_list      IN     VARCHAR2)
  AS
    l_tab string_api.t_split_array;
  BEGIN
    IF TRIM(p_list) IS NOT NULL THEN
      l_tab := string_api.split_text(p_list);
      FOR i IN 1 .. l_tab.COUNT LOOP
        UTL_SMTP.rcpt(p_mail_conn, TRIM(l_tab(i)));
      END LOOP;
    END IF;
  END;
BEGIN
  l_mail_conn := UTL_SMTP.open_connection(p_smtp_host, p_smtp_port);
  UTL_SMTP.ehlo(l_mail_conn, p_smtp_host);
  UTL_SMTP.auth(l_mail_conn, p_user_name, p_password);
  UTL_SMTP.mail(l_mail_conn, p_from);

  process_recipients(l_mail_conn, p_to);
  process_recipients(l_mail_conn, p_cc);
  process_recipients(l_mail_conn, p_bcc);

  UTL_SMTP.open_data(l_mail_conn);
  
  UTL_SMTP.write_data(l_mail_conn, 'Date: ' || TO_CHAR(SYSDATE, 'DD-MON-YYYY HH24:MI:SS') || UTL_TCP.crlf);
  UTL_SMTP.write_data(l_mail_conn, 'To: ' || p_to || UTL_TCP.crlf);
  UTL_SMTP.write_data(l_mail_conn, 'From: ' || p_from || UTL_TCP.crlf);
  UTL_SMTP.write_data(l_mail_conn, 'Subject: ' || p_subject || UTL_TCP.crlf);
  UTL_SMTP.write_data(l_mail_conn, 'Reply-To: ' || p_from || UTL_TCP.crlf);
  UTL_SMTP.write_data(l_mail_conn, 'MIME-Version: 1.0' || UTL_TCP.crlf);
  UTL_SMTP.write_data(l_mail_conn, 'Content-Type: multipart/mixed; boundary="' || l_boundary || '"' || UTL_TCP.crlf || UTL_TCP.crlf);
  
  IF p_text_msg IS NOT NULL THEN
    UTL_SMTP.write_data(l_mail_conn, '--' || l_boundary || UTL_TCP.crlf);
    UTL_SMTP.write_data(l_mail_conn, 'Content-Type: text/plain; charset="iso-8859-1"' || UTL_TCP.crlf || UTL_TCP.crlf);

    UTL_SMTP.write_data(l_mail_conn, p_text_msg);
    UTL_SMTP.write_data(l_mail_conn, UTL_TCP.crlf || UTL_TCP.crlf);
  END IF;

  IF p_attach_name IS NOT NULL THEN
    UTL_SMTP.write_data(l_mail_conn, '--' || l_boundary || UTL_TCP.crlf);
    UTL_SMTP.write_data(l_mail_conn, 'Content-Type: ' || p_attach_mime || '; name="' || p_attach_name || '"' || UTL_TCP.crlf);
    UTL_SMTP.write_data(l_mail_conn, 'Content-Transfer-Encoding: base64' || UTL_TCP.crlf);
    UTL_SMTP.write_data(l_mail_conn, 'Content-Disposition: attachment; filename="' || p_attach_name || '"' || UTL_TCP.crlf || UTL_TCP.crlf);

    FOR i IN 0 .. TRUNC((DBMS_LOB.getlength(p_attach_blob) - 1 )/l_step) LOOP
      UTL_SMTP.write_data(l_mail_conn, UTL_RAW.cast_to_varchar2(UTL_ENCODE.base64_encode(DBMS_LOB.substr(p_attach_blob, l_step, i * l_step + 1))) || UTL_TCP.crlf);
    END LOOP;

    UTL_SMTP.write_data(l_mail_conn, UTL_TCP.crlf);
  END IF;
  
  UTL_SMTP.write_data(l_mail_conn, '--' || l_boundary || '--' || UTL_TCP.crlf);
  UTL_SMTP.close_data(l_mail_conn);

  UTL_SMTP.quit(l_mail_conn);
END;