oracle 发邮件遇收信人不存在处理

loop
                OPEN get_mailid;
                    M_MAILID_W:=null;
                    LOOP
                    FETCH get_mailid INTO m_mail_id;
                       EXIT WHEN get_mailid%NOTFOUND;
                       if M_MAILID_W is null then
                          M_MAILID_W:=m_mail_id;
                       else
                           M_MAILID_W:=M_MAILID_W || ',' || m_mail_id;
                       end if;
                    END LOOP;   
                close get_mailid;
                begin
                    SM('TTMC_GRP@CPT',M_MAILID_W,M_Title,M_CONTENT);
                    exit;---when i>0;
                    exception
                  when others then
                    M_sqlcode:=sqlcode;
                    M_sqlerrm:=sqlerrm;
                    if M_sqlcode=-29279 then         ---No such user
                      M_MAILID_W:=substr(m_sqlerrm,instr(m_sqlerrm,'...',1)-8,8);
                      delete mes_mail where mail_Id=M_MAILID_W;
                      commit;
                    ELSE
                      EXIT;
                    end if;
                 end;
            end loop;