Is Session_End event supported in all session modes ?

The Session_OnEnd event is only supported when the session-state HttpSessionState.Mode property value is InProc, which is the default. If the session-state Mode is set to StateServer or SQLServer, then the Session_OnEnd event in the Global.asax file is ignored. If the session state Mode property value is Custom, then support for the Session_OnEnd event is determined by the custom session-state store provider.