Outlook Cache Mode, in the Application Installation & Compatibility forum on BrianMadden.com

Is there any way to enable cache mode running outlook on a PS server? I have a client that is having huge problems with delays when switching between folders in Outlook. Their Exchange servers are located across a WAN from the PS servers. We never had this problem before switching to Citrix because we were using local installs of Outlook and Cache mode was turned on.

Thanks
-OK

Cached Exchange Mode is disabled out of the box on Terminal Server. I don't think there is a way around that and you really don't want to go there as you would be holding multiple copies of mailboxes across multiple servers. And first time connects will have to suck down all the messages for every TS server they hit. It sounds like a bad idea.

Are you using Exchange 2003? If so I would suggest a WAN compression device like Riverbed Steelhead that has Exchange Acceleration built in. http://www.riverbed.com/solutions/accelerate/microsoft_exchange.php

I have spent part of the day looking for a cache mode solution on TS/Citrix. It seems everyone is worried about filling up the local disk of the TS/Citrix box. I'm not concerned about disk as we use separate hybrid profile servers for user created data, so the user created data follows them no matter what Citrix box they happen to be using.

I still have not found the right setting for Outlook 2003 Cache Mode to work on Citrix 4.5 yet. Any help would be greatly appreciated.

Michael

Hi,

You can enable cached mode in the registry on a Windows XP machine by setting this reg value:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\11.0\Outlook\Cached Mode

"enable"=dword:00000001

There are probably other keys/values too.

I don't think this will work on a Citrix server though. I personally wouldn't do it as it's not supported and MS must have disabled it for a reason.

http://office.microsoft.com/en-gb/help/HA011402681033.aspx

The reasons I think it's disabled are the following:

1. Cached mode downloads a local OST (offline storage file) copy of the user's mailbox. This file can NOT roam between computers, so it's useless in a terminal server farm with more than one server.

2. On a single user machine, syncronizing the OST for one user can tax the machine. Imagine 20+ users doing this at the same time.

3. Terminal Servers should normally be in close proximity to back-end data, i.e. Exchange, SQL Server, Profile & File Servers, so the need for offline copies of each mailbox doesn't make much sense.

4. Since the OST is a copy of the mailbox, would you really want to use up the TS local disk storing copies of each user's mailbox. This file can't roam (refer to number 1).

I think it's disabled for valid reasons.

I've been looking for ages now to be able to do the same thing! I have users working on a remote site, using a hosted Exchange service. So basically, three sites, with Terminal Servers in the middle. There is no way I can bring the Exchange to the same network, or move the Terminal Servers to the Hosted Exchange's site.

For e-mails, everything runs quite fine, but when attachments need to be opened, it's a whole different story. So Cached Exchange Mode should be super, if only it were possible. We're not talking about that many users, so I'm not concerned with any performance issues.

Basically, has anybody ever been able to enable the use of ost files on a Terminal Server, or is there another tool/config I can use to have some kind of background synchronization between the hosted Exchange and the Outlook 2003 client?
I've tried the reg key mentionned above, the 00036601 reg key trick, the Outlook GPO settings, ... And running the Outlook locally isn't an option either, since we need it to be on the same machine as another application that needs to run on the Windows 2003 Terminal Server.

Any help or experience you had in the past will be very much appreciated.

Mathias