I blogged about the Outlook RPC dialog box while ago. I found out more users seek out cure for the Outlook RPC pop-up cancer.
Here are some step by step information you can check to resolve the issue.
1. Outlook Cached Mode. I repeat…Outlook Cached Mode. Most user’s Outlook RPC issues end here.
I know few users who hate Outlook Cached Mode for life. Their reason is it’s slow. For example, User A from 10 cubes far walk to the another user B asking about the email he sent. User B is puzzled and says he didn’t receive it yet. While they are talking, User B’s Outlook notifies about a new email from user A. Now do I have say why they hate it?
But as a Exchange Admin, you should enforce "Outlook Cached Mode" to your users for their own good. Plus you will earn less number of RPC calls to the server.
2. Analyze when they are getting Outlook pop-ups exactly. You can have them note down the information from the popup box saying "Outlook is trying to retrieve data from …".
If the pop-up message mentions
- Global catalog server, then you know where to look. You GC may be slow or unavailable or even replication latency issues. If required, Add one more Global Catalog server on your site.
- Remote Exchange Server, then its most likely Outlook is trying to access a Public Folder from Remote Exchange Server. Find out which Public folders your local users trying to access, make a local replica on your local Exchange server
- Local Exchange Server, then ask the user what exactly s(he) is trying to access when pop-ups started. Here is interesting part. Your user is just trying to access his/her own mailbox and nothing else. Find out how many items on their folders like Inbox, Calendar, Contacts, etc., If any folder exceeds 3000 items and above, that is the problem according to Microsoft. See here: Outlook users experience poor performance when they work with a folder that contains many items on a server that is running Exchange Server
- Local Exchange Server and user is trying to access other user’s calendar or trying to book a meeting with many attendees. Now this is really interesting. User may be using Outlook Cached Mode, that doesn’t mean other user calendar also cached locally when the user trying to access other user’s calendar. For me, there is no solution here…user may have to live with it. You could turn off the Meeting Planner settings. Check this MSKB: How to troubleshoot the RPC Cancel Request dialog box in Outlook 2003 or in Outlook 2002. To turn off the meeting planner,
1. On the Tools menu, click Options.
2. On the Preferences tab, click Calendar Options.
3. In the Calendar Options dialog box, click Planner Options.
4. In the Meeting Planner section, click to clear the Show popup calendar details check box.
5. Click OK three times
3. Check the Exchange server performance like processor, network, memory especially the RPC performance.
To check the RPC performance,
- Open "Performance" console on your Exchange Server
- Click + button to add new counter
- Select Exchange IS from the drop down list and Select and Add the following counters: RPC Requests, RPC Requests per second
- Monitor the counter values in Peak hours or when users are complaining
Here is the RPC performance excerpt from here: Outstanding RPC requests reached maximum threshold
The average value of the RPC Requests performance counter should be under 30 at all times. By default, the maximum value for RPC requests is 100. Therefore, unless it is configured otherwise, the Microsoft Exchange Information Store service can service only 100 RPC requests at the same time before all new RPC operations will be rejected and users will not be able to connect to the server until the RPC requests drop below 100. The server will become unresponsive, mail flow may stop. The Outlook users may receive the RPC cancel Request dialog box.
The reason for increased RPC calls to the server are,
a) BlackBerry Enterprise Server. When we talk about RPC requests, I have to mention about the ‘infamous’ BlackBerry Enterprise Server. For every BES user account, BES server generates triple, sometimes five times of, the number of RPC quests to the server.
b) Many user falling love with Desktop Search products like Google Desktop, MSN Desktop Search, etc., these products constantly indexes the mails. Make sure your users are using "Outlook Cached Mode" along with Desktop Search products.
c) Users changing Outlook Views more often. Say a user’s inbox has 6000 mail items. He clicks the column headers to sort the mail by Sender or Received Data/time or by Flags. If the user is in Outlook Cached Mode, view changing need not to contact the server.
d) User is running Outlook more than once in two different machines. Like user already running the Outlook on her/his desk and one in Lab. Inform users to try to run Outlook only once
e) Outlook Add-ins, third-party programs, home grown applications accessing Exchange server.
You can download and use Exchange Server User Monitor. This tool will tell you who is abusing the Exchange server. You may hunt them down and find out why their Outlook generates high number of RPC calls.
You should also run Exchange Best Practice Analyzer and Exchange Troubleshooting Assistant to analyze your server.
4. Check the Network latencies if the Exchange server is in remote site.
Consider implementing Outlook Anywhere aka RPC/HTTP access for the remote users.
Update: If you are using Exchange 2007, you could try Client RPC Throttling. Very intesting feature. Check it out here: http://technet.microsoft.com/en-us/library/cc540454(EXCHG.80).aspx
Check this MS support knowledge base article for more information: How to troubleshoot the RPC Cancel Request dialog box in Outlook 2003 or in Outlook 2002
I hope best for you.
Anand, the Architect 