I've worked with a little bit with groupwise, but only in sending appointments. Here is the code I did. Let me research alittle more. Mean while see if this helps.

						ng = CREATEOBJECT("NovellGroupwareSession")
						if vartype(ng)='O' && Group Wise object was successfully created    
							gobj = ng.Login
							mailmsg = gobj.MailBox.Messages.Add('GW.MESSAGE.APPOINTMENT')
							mailmsg.FromText=ALLTRIM(.cbo1.value)
							mailmsg.Subject=ALLTRIM(.e1.value)
							hldbt=ALLTRIM(.e1.value)+". The due date is: "+DTOC(.txtTc_duedate.value)+" Comments: "+ALLTRIM(.e2.value)
							mailmsg.BodyText=hldbt
							mailmsg.NotifyWhenDeleted=0
							mailmsg.NotifyWhenAccepted=0
							mailmsg.NotifyWhenOpened=0
							dt=.txtTc_notify.value
							dt=DTOT(dt)+12*3600
							mailmsg.StartDate=dt
							mailmsg.OnCalendar="TRUE"
							mailmsg.Place="PROBATION"
							cSendTo ='KERNMAIL:'+ALLTRIM(.txtTc_email.value)
							recpt=mailmsg.Recipients.Add(cSendTo,"NGW",'0')
							recpt.Resolve
							mailmsg.Send
						ENDIF 
						RELEASE ng

Also, I have the pdf groupwise developers guide if you need it.

thanks
Nick