((MXECHO))

I ran across a situation the other day that I thought could use some additional explanation. In this case when users would open a Public Folder for the first time through Outlook the Outlook client would lock up or become unresponsive. If the user closed (end task) Outlook and went back into the same Public Folder then it opened quickly. If they waited (not ending task) then the Outlook client would “hang” for 40 seconds to 2 or 3 minutes – depending on how many items were in the Public Folder, but the folder would eventually open. The more items, the longer the wait time. As testing the Admin, created new profiles, and even restarted the computer several times to test. The issue ONLY occurs the first time they open the folder, after the first long pause, the folder opens fast each and every time. These clients were online clients. To clarify, this was for each folder in the Public Folder hierarchy. 

When we open a Public Folder in Outlook online mode the server creates the view for your client based on the view requested by the client. On most clients the view is standard, meaning they have not added any additional columns or modifications. In this standard scenario, the server has the general view already created as a table and can provide this view to the client quickly. However if your client is requesting a different view, then the server must create this view as a table in the store in order to present the view to the client. Once the view is created it is kept for a given amount of time (varies depending on Exchange version, but at least days) and is reused the next time it is requested. This is why the users would see the data quickly after the initial delay.

Do you have any control over these views or workarounds for the initial delay? There are two attributes on the public folder store that can control how many cached views are held and how long they are held for, msexchmaxcachedviews and msexchagingkeeptime. The biggest impact you can have on this initial delay is lowering the item count for the folders you are trying to access. The more items in the folder, the longer it will take to present the new view to your client. The other option you have is to reset your clients views back to default. You may  not even realize that you are using a view that is not common. The Outlook switch /cleanviews will reset your clients views back to default. This will NOT clear any views from the server, just the settings on the client.

This same type of behavior can be seen in mail folders as well, not just Public Folders. In fact many people may see this after a mailbox move as the views associated with the mailbox will needs to be recreated. Once the view is created, as long as it is accessed frequently enough the view will not be deleted from the server and the clients performance will remain quick. If the user goes on vacation….and doesn’t access their custom view for a given amount of time, then when they return they will also more than likely see some initial delays while those views are being created.

For additional information on this behavior see this TechNet article http://technet.microsoft.com/en-us/library/cc535025.aspx