We have Exchange accounts in Outlook 2010 and the Global Address List would not update. One reason was due to an error on our server (address in another post), but then the default times to update are 24 ours, and that’s too long. On our internal systems, we want Cached Mode exchange accounts, but direct/real-time addess to the Global Address List in Active Directory.
1.
Add this to a new registry file and/or add to your user’s registry (not system, each user on workstation). Create a text file on your desktop, copy/paste the text below, save, then double click to add to your registry:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Cached Mode]
"DownloadOAB"=dword:00000000
The above is for Outlook 2010, but for 2007 and 2003, replace the 14.0 with 12.0 and 11.0 respectively.
2.
If you have and OAB files, you need to remove them. In this folder:
%userprofile%\AppData\Local\Microsoft\Outlook
If you see “Offline Address Books”, rename that folder. Close Outlook and reopen.
You should now have direct GAL access and updates are immediate.
Reference more detail here:
http://support.microsoft.com/kb/841273