<A target="_blank" href="http://www.ns-tech.com/blog/geldred.nsf/plinks/GELD-7XGKKK">Gregg Eldred says, yes, there are memory leaks in Domino 8.5.x.</A> There is a HotFix that helps with that problem, but may cause others. He's provided a link to the Technote in case you need to request the HotFix.