MAIL_RECIPIENT ,MAIL_SENDER option

Hi All,

can you plz let me know why sap has provided the following option in FM CALL FUNCTION 'OPEN_FORM'.

A.MAIL_RECIPIENT

B.MAIL_SENDER

C In DEVICE Parameter the value is TELEFAX

Does it mean that we can send the Email and Fax by providing these detail.

if no what is the use of these parameters.

if yes where we will define subject field in parameter for Email and Fax Number.

Tahnks in Advance.