Indexing additional mailboxes in Outlook 2007

Miguel Garrido — Sat, 16 Jan 2010 05:24:54 GMT

I recently came across an issue where an administrative assistant needed to search her boss’s huge mailbox while it was attached in Online mode to her Outlook profile. Normally, Outlook search will work for certain folders (like Calendar and Contacts) because it caches those folders from attached mailboxes so that they can be indexed; however in this case the amount of items in each of those folders was either too large or something else was going on and search just wasn’t working.

After searching online, I was able to find out about the CacheOthersMail registry value which can be set in HKLM\Software\Microsoft\Office\12.0\Outlook\Cached Mode and is looked for by Outlook after a post Office 2007 SP1 hot fix (which is included in Office 2007 SP2). This value will instruct Outlook to cache any attached mailboxes in the user’s OST file – this being useful because it increases the access speed of the mailbox significantly and I thought should allow the indexer to index the mailbox. Much to my chagrin, I found that the mailbox was still not indexed after creating this value in the proper registry key (but I could confirm that the mailbox was indeed cached); I had to continue looking.

It was then that I was pointed to the following (excellent) blog post by Mike Lagase: Windows Desktop Search Indexing in Outlook. This blog post detailed an interesting setting (which could be potentially dangerous when used improperly): Enable Indexing of Delegate Mailboxes. This setting, along with other useful Group Policy settings for Windows Desktop Search 4 when a user needs to index mailbox contents are discussed in Mike's blog post.

Make sure to read the blog post for more details, however my fix was to set the CacheOthersMail registry value along with enabling the Enable Indexing of Delegate Mailboxes policy. The end result of this was Windows Desktop Search 4 indexing the contents of the already cached attached mailbox.

The administrative assistant is now happy again that she can search her boss’s mail like she was able to in the past.

About mailbox searching in Outlook 2003/2007 [with Exchange]

Miguel Garrido — Fri, 11 Sep 2009 04:27:23 GMT

A quick tip for anyone who is experiencing issues searching their mailbox on Outlook 2003 (with or without Windows Search) and Outlook 2007 (preferably with Windows Search enabled on non-Vista/7 machines). If the mailbox mode is in Online mode, that is, it is not in Cached Exchange Mode, you might want/have to enable Cached Exchange Mode for Outlook 2003 in order for your searches to work properly.

Now I have found that for Outlook 2007 search to work (though I have to admit, I have only verified these findings when Windows Search was installed), you need to also enable Cached Exchange Mode. I can only guess that the reasoning behind this is that the indexer can index your mailbox locally and thus provide you with the search results you need (in a fast responsive manner) when your mailbox is stored on your hard drive as an OST file. Now (and this is only speculation since I haven’t bothered to look this up) it is very possible that if the Exchange Server is being indexed and you are running Exchange 2007 and Windows Server 2008 or Windows Search on Windows Server 2003 and Windows Search on your workstation that Outlook 2007 will provide you with search results without having to enable Cached Exchange Mode by passing the search request to the indexer on the server running Microsoft Exchange, similar to how Windows Search retrieves file search results across the network.

However, the whole point of this post is that it is worth a try enabling Cached Exchange Mode if you have a search related issue on an Outlook client that connects to an Exchange Server and everything else you’ve tried isn’t working, like rebuilding the index, or reinstalling Windows Search, etc.