declare
    Subject IN VARCHAR2 := 'Test';
    Message IN VARCHAR2 := 'Test message';
    ToEmail IN VARCHAR2 := 'test02@mail.com';
    Attachment IN CLOB;
    FilenameAttachment IN VARCHAR2;
    FromEmail IN VARCHAR2 := 'test01@mail.com';
    FromName IN VARCHAR2 := 'TEST';
    Priority IN INTEGER := 3;
    ContentType IN VARCHAR2 := 'application/excel;';
    con UTL_SMTP.connection;
    AttachmentLength PLS_INTEGER;
    amount BINARY_INTEGER := 30000;
    BUFFER VARCHAR2(32000);
    offset PLS_INTEGER := 1;
    MIME_BOUNDARY  VARCHAR2(50) := '=====Boundary======';
begin
    -- здесь Attachment вычитывает файл DBMS_LOB.LOADCLOBFROMFILE

    -- setup mail header
    con := UTL_SMTP.OPEN_CONNECTION('localhost', 25);
    UTL_SMTP.helo(con, SYS_CONTEXT('USERENV', 'DB_DOMAIN'));
    UTL_SMTP.Mail(con, LOWER(FromEmail));
    UTL_SMTP.rcpt(con, LOWER(ToEmail));
    UTL_SMTP.open_data(con);

    UTL_SMTP.write_data(con, 'From: "'||FromName||'" <'||LOWER(FromEmail)||'>'||UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, 'To: <'||LOWER(ToEmail)||'>'||UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, 'Subject: '||Subject||UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, 'X-Priority: '||Priority||UTL_TCP.CRLF);

    UTL_SMTP.write_data(con, 'Mime-Version: 1.0' || UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, 'Content-Type: '||MIME_MIXED||' boundary="'||MIME_BOUNDARY||'"' || UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, '--'||MIME_BOUNDARY || UTL_TCP.CRLF); 
    UTL_SMTP.write_data(con, 'Content-type: text/plain' || UTL_TCP.CRLF); 

    -- Mail Body
    UTL_SMTP.write_data(con, UTL_TCP.CRLF);
    UTL_SMTP.write_raw_data(con, UTL_RAW.cast_to_raw(Message));
    UTL_SMTP.write_data(con, UTL_TCP.CRLF);

    -- put footer to end of mail
    UTL_SMTP.write_data(con, UTL_TCP.CRLF || UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, 'Message from User001 sent at '||TO_CHAR(LOCALTIMESTAMP, 'yyyy-mm-dd hh24:mi:ss'));
    UTL_SMTP.write_data(con, UTL_TCP.CRLF);

    -- Mail Attachment
    UTL_SMTP.write_data(con, UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, '--'||MIME_BOUNDARY || UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, 'Content-Type: '||ContentType||' name="'||FilenameAttachment||'"'|| UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, 'Content-Disposition: attachment; filename="'||FilenameAttachment||'"'|| UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, UTL_TCP.CRLF);

    AttachmentLength := DBMS_LOB.GETLENGTH(Attachment);
    plog.dolog('SENDMAIL_PKG.SendMail: AttachmentLength='||AttachmentLength);
    LOOP
        EXIT WHEN offset > AttachmentLength;
        DBMS_LOB.READ(Attachment, amount, offset, BUFFER);
        plog.dolog('SENDMAIL_PKG.SendMail: BUFFER='||BUFFER);
        UTL_SMTP.write_raw_data(con, UTL_RAW.cast_to_raw(BUFFER));
        offset := offset + amount;
    END LOOP;

    UTL_SMTP.write_data(con, UTL_TCP.CRLF);
    UTL_SMTP.write_data(con, '--'||MIME_BOUNDARY||'--' || UTL_TCP.CRLF);

    CloseMail(con);
end;