Progressive OS resource consumption CAS 2.6 & Outlook 2003

I think I may have found the source of some of the instability problems beseting the use of CAS 2.6 with Outlook 2003.

On my system, CAS32.exe consumes more and more OS handles (& GDI objects) the longer the system has been running. These accumulate at a rate of about 3600 per day on my system, which does a send receive every minute or so. Outllook itself (when CAS is enabled) seems to consume more and more handles with time - maybe 600 per hour (!) - though I need to confirm this with a longer monitoring period.

As there is an OS limit (somewhere in the tens of thousands) things are bound to go pear shaped after a day or so! Meanwhile possible (untested) workarounds here: Atomic I/O letters column #67 & look for topic: “Still plenty of 0s, but you’re out of 1s”. Also read this, if first fixes don’t work. Ohad's Blog - Max Num. of Open Windows under XP/2003/VISTA - Resolved !. (I ended up using the following values: 1024,20480,768. Do make a system restore point before trying these!

Hope this helps


  1. Your Operating System: XP SP3 32 bit
  2. Other Security and Utility Software Installed: Avira Basic (mail filter disabled), CIS, CSE, CMS, CVE, Safesurf, Actual Window manager, Antifreeze, Clipmate, Idrive, Sysinternals process explorer.