Workflow agents email calling

Hi all,

I have Created a Workflow to send mail. It is working well while executing through SWDD by Agent ID as Input. Now I am calling that workflow from program (SE38) using the below function module

MOVE 'US' TO agents-otype.

MOVE '123456' TO agents-objid.

APPEND agents.

CALL FUNCTION 'EWW_WORKFLOW_START'

   EXPORTING

     x_task                = 'WS99900059'

  TABLES

    x_agents              = agents

* EXCEPTIONS

*   INVALID_TASK          = 1

*   NO_ACTIVE_PLVAR       = 2

*   START_FAILED          = 3

*   GENERAL_ERROR         = 4

*   OTHERS                = 5

           .

IF sy-subrc <> 0.

* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO

*         WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

ENDIF.

But I am not getting any mails in my workflow inbox.

Please help.

Thanks,

Uday