Ok, then a hidden item is the way to go.
What kind of data are you storing? Is it really per-folder? If not, you can
store everything as a hidden message in, say, Inbox.
I don't see this as a performance problem as long as you read the data only
wwhen you actually need it and cache it in memory for the lifetime of your
app.

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

"j" wrote in message
oups.com...


The reason to store data on the folder level rather than registry or
file systems is beacause
if some user change his machine or format it's machine all data stored
on registry or file system level are
erased or not available (in case user logged in to other machine and
open Outlook). However when i store
data on folder level, it doesn't matter, cause when user log in to
some machine and configured Outlook to work
against Exchange all data and my data also are syncronized.

What do you think???


Thnask in advance.