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Send mails in Chinese characters

Hi all

I'm using UTL_SMTP package to send mails in a stored procedure.
My database character set is set to traditional Chinese
All Chinese characters received by the mail clients are converted to "?".

I think this may happen in all multi-byte characters.
Is there ever a way in PL/SQL to solve this problem ?

Thanks in advance.

1 Solution


From what I understand,  you are going to need to use the MIME format.  

As from this clip:
According to the Oracle documentation, the original SMTP protocol communicates using 7-bit
 ASCII. Using UTL_SMTP, all text data (in other words, those in VARCHAR2) will be converted to
 US7ASCII before it is sent over the wire to the server. When the target SMTP server supports
 8BITMIME extension, users of multi-byte databases may convert their non-US7ASCII, multi-byte
 VARCHAR2 data to RAW and use the write_raw_data() API to send multi-byte data using 8-bit
 MIME encoding.

How to send MIME format:
Put the following lines  right after the message subject that you send to utl_smtp.data.

 'MIME-Version: 1.0' || crlf ||
 'Content-type: text/plain; charset=iso-8859-1' || crlf ||
 'Content-transfer-encoding: 7bit' || crlf ||
 '' || crlf ||

(use the appropriate characterset in place of  "charset=iso-8859-1")

I think this might work -- give it a try...

AlbertYouAuthor Commented:

Hi Laski

I have tried your way, it did not work.
I don't know what does
 "right after the message subject" mean.

However, your answer gives me a good hint that
this problem is derived from MIME format.

I have solved this problem by using the UTL_RAW package.
The following is my code.

   c utl_smtp.connection;
   PROCEDURE send_header(name IN VARCHAR2, header IN VARCHAR2) AS
      utl_smtp.write_raw_data(c, utl_raw.cast_to_raw(name || ': ' || header || utl_tcp.CRLF));
   PROCEDURE put_line ( p_line_text in varchar2) is
      utl_smtp.write_raw_data(c, utl_raw.cast_to_raw(p_line_text || utl_tcp.CRLF));
   c := utl_smtp.open_connection('smtp-server.acme.com');
   utl_smtp.helo(c, 'foo.com');
   utl_smtp.mail(c, 'sender@foo.com');
   utl_smtp.rcpt(c, 'recipient@foo.com');
   send_header('From',    '"Sender" <sender@foo.com>'');
   send_header('To',      '"Recipient" <recipient@foo.com>');
   send_header('Subject', 'Chinese subject' );
   put_line(''); -- Do not remove this line, otherwise the mail content will be empty !!!
   put_line('Chinese messages');
  WHEN utl_smtp.transient_error OR utl_smtp.permanent_error THEN
         'Failed to send mail due to the following error: ' || sqlerrm);

Thanks anyway.


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