Tried that. No Luck!

I guess the dll is hard wired to the system32 dir.

Is there a sensible reason why a zip class is not available as part of the OS other than MS never got round to doing it?

The need for this comes from unattended automatic emailing with very large attachements resulting from data extraction on a daily basis.

Server storage is caned by this sort of thing.
If the OS people cannot do this how about the Outlook team building this into MAPI?