[Exim] Relay uring "x@y"[IP]

Boys and Girls,

I need some assistance in a BIG problem....

One of my Exim mail servers was Black listed as relay-open. I have beem thru all the manuals and there I've got that the directive

percent_hack_domains=*

would close this opening... indeed it closed the x%y@[IP}, but not the "x@y"[IP] one.. :-(

I have upgraded from the 3.12 to 3.35 but it continues to accept .. :-(

can anyone help me?

TIA

Fred