OLXP: Outlook Requesting Data Popups

Many people after upgrading to Outlook XP notice the "requesting data from server" dialog boxes. Why is this? This can be for many reasons but let's go through some of the common issues and suggestions:

1) Network problems - if the Outlook client has only a small amount of bandwidth to get to the server, the client may have to wait for data before it can continue. 

If you are connecting over a VPN it may be wise to make sure you are not dropping/fragmenting packets because of the reduced frame size allowed over VPN.  This stems from the DNF (Do Not Fragment) bit being set on most MAPI traffic, which means if the packet plus the VPN encryption header information overhead hits 1500 (or whatever your frame size limit is) the entire frame is dropped.   If this is happening to you the best bet is to make sure your frames that are sent are smaller than that limit by tweaking the registry on the server and set your MTU down.

There are a few more ideas to follow in this article.  The article refers to this as a "Black Hole Router problem"  http://support.microsoft.com/?id=314825

Other network problems are things such as overall latency and reduced bandwidth.   These can cause these slowdowns and requesting data messages.


2) Address/Name lookup problems - If the client doesn't have a full offline address book the the client may have to make frequent trips to the GC for name lookups. If the GC is busy (overloaded) or across the WAN it make take time to do an address lookup.


3) Corrupt OST file. The user may have a corrupt Offline Store File, try recreating it.


4) Name resolution for Exchange Servers or DC/GCs. Again if you are across a WAN and do not have WINS and DNS resolution for the exchange servers you will either need to correct this or create local hosts and/or lmhosts files to resolve this issue.