try Shawn's script with a little change (don't forget to replace the user AD path with the correct one):
break on
$user = GetObject("LDAP://st8en1.dhw.zain.com.st/CN=noor NIaa.,OU=Test,OU=Messaging,DC=zain,DC=com")
if $user
? "user retreived"
else
? "@ERROR ; @SERROR"
endif

exit 1

2) What is the mail server ?
3) I don't understand for the internet authentification server :is it completely independant from the AD domain ?