To change the update frequency for offline global address book in Outlook, you need to define an individual send/receive group, and configure the update interval for this group.

1. Click Send / Receive > Send/Receive Groups > Define Send/Receive Groups. See screenshot:

2. In the opening Send/Receive Groups dialog box, please click the New button. See screenshot below:

3. In the popping out Send/Receive Group Name dialog box, name the new group, and click the OK button. See screenshot above.

4. Now the Send/Receive Settings dialog box opens, please do as follows:
(1) Select the email account whose offline global address book you will change update frequency for in the Accounts pane;
(2) Check the Include the selected account in this group option;
(3) Only check the Download offline address book option in the Account Options section;
(4) Make sure that the Include the selected account in this group option is not checked in other email accounts, and click the OK button.

5. You return to the Send/Receive Groups dialog box, please check the Schedule an automatic send/receive every x minutes option in the Setting for group section, specify the update interval among this option, and click the Close button. See screenshot:

Note: It’s optional to check the Schedule an automatic send/receive every x minutes option in the When Outlook is Offline section, and specify the update interval among the option.

Define a send /receive group in Outlook