The Global Address Book (GAL) is a directory of available contact information for CUMC, NYPH and Columbia University faculty, staff and students.
If you go to Tools -- Download Address Book, does it successfully update?
Note: it takes up to 8 hours for the Offline Address Book to be distributed to Client Access Servers to which Outlook is connecting, so it may take up to 32 hours for the freshly generated Offline Address Book to be updated in Outlook client.
All versions: check Download changes since last Send/Receive box.
Knowing why the delay occurs means you won’t spend time troubleshooting it.
When a new email address is added to our company's Exchange server it doesn't show up immediately on my Outlook, and I suspect that it's because of the "cached mode".
To make new users show up in the GAL immediately, you can force a rebuild of the OAB.