How to send emails from SAP by using the Function Modules

Sending External email through SAP
What is the FM for sending the external email through SAP by attaching layout set  to it?
These are the FM for sending external email :-
SO_DOCUMENT_SEND_API1 
SAPoffice: Send new document with attachments via RFC 
SO_NEW_DOCUMENT_ATT_SEND_API1
(In 4.6C only, You can go to SE37 and click the documentation on how to use it. A sample program is provided there.)
SAPoffice: Send new document with attachments via RFC 
Note : If you are using FM SO_NEW_DOCUMENT_ATT_SEND_API1 then Export Parameter DOCUMENT_DATA-OBJ_DESCR contains the Subject. 
SO_NEW_DOCUMENT_SEND_API1 
SAPoffice: Send new document 


Sample Program :

REPORT ZREPORT_TO_EMAIL NO STANDARD PAGE HEADING .
DATA : BEGIN OF ITAB OCCURS 0,
PERNR LIKE PA0001-PERNR,
ENAME LIKE PA0001-BUKRS,
END OF ITAB.
DATA: body_message  LIKE soli OCCURS 5 WITH HEADER LINE,
receiver_list LIKE soos1 OCCURS 5 WITH HEADER LINE,
packing_list LIKE soxpl OCCURS 2 WITH HEADER LINE,
listobject LIKE abaplist OCCURS 10,
compressed_attachment LIKE soli OCCURS 100 WITH HEADER LINE,
w_object_hd_change LIKE sood1,
compressed_size LIKE sy-index.

START-OF-SELECTION.
SELECT PERNR BUKRS
INTO CORRESPONDING FIELDS OF TABLE ITAB
FROM PA0001
WHERE PERNR < 5.
LOOP AT ITAB.
WRITE :/02 SY-VLINE , ITAB-PERNR, 10 SY-VLINE , ITAB-bukrs, 50
SY-VLINE.
ENDLOOP.
 
* Receivers
receiver_list-recextnam = 'Giridhar_External@gmail.com'. "-->
* EMAIL ADDRESS
RECEIVER_list-RECESC = 'E'. "<-
RECEIVER_list-SNDART = 'INT'."<-
RECEIVER_list-SNDPRI = '1'."<-
APPEND receiver_list.
* General data
w_object_hd_change-objla = sy-langu.
w_object_hd_change-objnam = 'Object name'.
w_object_hd_change-objsns = 'P'.
* Mail subject
w_object_hd_change-objdes = 'Message subject'.
* Mail body
APPEND 'Message content' TO message_content.
* Attachment
CALL FUNCTION 'SAVE_LIST'
EXPORTING
list_index = '0'
TABLES
listobject = listobject.
CALL FUNCTION 'TABLE_COMPRESS'
IMPORTING
compressed_size = compressed_size
TABLES
in = listobject
out = compressed_attachment.
DESCRIBE TABLE compressed_attachment.
CLEAR packing_list.
packing_list-transf_bin = 'X'.
packing_list-head_start = 0.
packing_list-head_num = 0.
packing_list-body_start = 1.
packing_list-body_num = sy-tfill.
packing_list-objtp = 'ALI'.
packing_list-objnam = 'Object name'.
packing_list-objdes = 'Attachment description'.
packing_list-objlen = compressed_size.
APPEND packing_list.
CALL FUNCTION 'SO_OBJECT_SEND'
EXPORTING
object_hd_change = w_object_hd_change
object_type = 'RAW'
owner = sy-uname
TABLES
objcont = message_content
receivers = receiver_list
packing_list = packing_list
att_cont = compressed_attachment.