SAP to OUTLOOK

[ASSY, SOSTHENE]

configured my sap-connect.
        Users receive information in their OUTLOOK if my task created with
SELFITEM  and SENDTASKDESCRIPTION  is not a background  task.
        When I changed to the task to background task , I've received this
information ' Method SENTASKDESCRIPTION cannot be executed'.
        I've added a valid internet address to WF-BATCH but always the same
message.
 
        Any suggestions ??
 
        Thank.