If you have outlook 2003 clients on your network that is running exchange 2010 here some issues to bear in mind
Service Pack Level :
If you want outlook 2003 to be able to connect to Exchange 2010 then it must be service pack 3. If you don’t it will not work.
Encryption must be enabled in the Outlook profile if you would like to connect the client to Exchange 2010.
Under the Outlook Profile, choose “more settings” and then choose the Security tab. Make sure “Enable encryption between Outlook and the Exchange Server” is ticked.
View our article here on how to connect outlook 2003 to Exchange 2010
Outlook 2003 in Online Mode
There is an issue where Outlook 2003 clients may run slow when configured in Online mode only. Users will notice things like moving items between folders and deleting items are slow and show lag . Enabling cached mode resolves this problem or alternatively you can follow these steps. This is a work around for this issue
On the server with the Client Access Role
- Install Exchange 2010 Update Rollup 1 and restart the server.
- Now make the following registry change.
- Create a DWORD called ”Maximum Polling Frequency” (without quotes)
- Make the value 10000
Note that this change is dynamic and clients will need to close and open Outlook again for the change to take affect.
Another things you can do to reduce the user impact include:
- turning off the preview pane.
- advising users to open the message and delete the open message, rather than deleting from the Inbox.