APEX

I’m trying to send an email message prepared in a CLOB and containing Cyrillic
characters.
But  . . . . all Cyrillic characters in the email are replaced with ’?’.

How to send Cyrillic characters using WWV_FLOW_MAIL?

Table structure:

create table messages
    (id number,
    subject varchar2(200),
    text clob,
    html_text clob /* Cyrillic */
    );

The process sending email:

begin
for c0 in (select subject, text, html_text
    from messages
    where id = :P413_ID) loop
   for c1 in (select email
        from members
        where id in (select member_id
            from member_groups
            where group_id = :P412_GROUP_ID)) loop
     if c1.email is not null then
        WWV_FLOW_MAIL.SEND(
            P_TO => c1.email,
          P_FROM => 'myemail@fixed.com',
           P_BODY => c0.text,
          P_BODY_HTML => c0.html_text, /* Cyrillic */
          P_SUBJ => c0.subject);
    end if;
    end loop;
 end loop;
end;