You can configure Send/Receive groups to specify how often Microsoft Outlook connects to your servers when you are working offline and to obtain new mail messages, send messages in your Outbox, and check for updates to RSS Feeds, Internet Calendar subscriptions, and Windows SharePoint Services 3.0 lists. You can also choose to include or exclude a Send/Receive group when you press F9 (Send/Receive All) when you work offline.
On the Tools menu, point to Send/Receive, point to Send/Receive Settings, and then click Define Send/Receive Groups.
Keyboard shortcut To open the Send/Receive Groups dialog box, press CTRL+ALT+S.
Select the send/receive group that you want to modify.
Under Setting for group send/receive group name, under When Outlook is Offline, select the Schedule an automatic send/receive every n minutes check box.
Enter a number between 1 and 1440. The latter number schedules an automatic send/receive once daily.