hide read reciept?

hi

i m using 'BBP_OUTPUT_PO_DOC_SEND_ADB' this fm to send adobe attachment tthrough mail

i want to hide read reciept ?

   try.
                send_request = cl_bcs=>create_persistent( ).

   lo_send_document = cl_document_bcs=>create_document(
                          i_type    = lv_mail_format
                          i_text    = lt_mailbody
                          i_length  = lv_mailbody_size
                          i_subject = lv_doc_subject_50 ).


*     add document to send request
                CALL METHOD send_request->set_document( lo_send_document ).
*
                send_request->set_status_attributes( i_requested_status = 'E'  ). "Block Read Receipts
*     ---------- send document ---------------------------------------
                CALL METHOD send_request->send(
                  EXPORTING
                    i_with_error_screen = 'X'
                  RECEIVING
                    result              = sent_to_all ).
                IF sent_to_all = 'X'.
                ENDIF.

can u please suggest ?