you might want to alter the "Cached Exchange Mode synchronization timing"
To provide a good balance between usability and network efficiency, the timing of synchronization communications between Outlook 2003 and Exchange Server 2003 has been optimized by using synchronization timers.
You can change these synchronization timer values by creating and by modifying the following registry keys and values under the HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\11.0\Outlook\Cached Mode registry key:
Upload=dword:0000000f (default is 15 seconds).
Download=dword:0000001e (default is 30 seconds)
Maximum=dword:0000003c (default is 60 seconds)
By default, whenever the client is in Cached Exchange Mode and a user makes a local change, the Upload timer starts. Changes have the following effects:
If a local change occurs during the 15-second window of the Upload timer, the Upload timer restarts.
If no other local changes before the 15-second window expires, the data is synchronized to the server.
If changes continue to occur before the 15-second window expires, all changes are synchronized to the Exchange Server computer after one minute. There is no additional delay.
When the Exchange Server computer notifies Outlook 2003 of a change, the Download timer starts. Outlook delays receiving the change information. This behavior reduces server load and improves network performance, because Outlook is frequently notified of multiple server changes in quick succession. All notifications that occur in the 30-second window of the Download timer are grouped together, and then they are processed at the end of the timer. The timer is then reset to wait for the next server notification. When a new mail notification is received, Outlook 2003 synchronizes folders where new or changed items reside. Unread counts are updated, and then any rules are processed.
