Outlook gal not updating in cached mode
If they have an Exchange account, then they are "mailbox-enabled" and the GAL determines which Exchange Server hosts their mailbox.
If they do not have an Exchange account (they are still mail-enabled), the GAL says their email is "[email protected]" and is told to route that mail back up to the relays, and then it's up to the relays to look up that email redirection field and deliver their mail appropriately.
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".
Another option is to only disable the Global Address List from being included, so it will also be a live copy from the exchange server.
You have set up Outlook Photos and added photos as you require, however the photos are not appearing in Microsoft Outlook 2010.
The Global Address List (GAL) has not updated from Active Directory.
Depending on the size of your organization and changes to default settings, it could take days before a new user can make its way into the OAB and onto your local copy.
It's also possible that there's an issue with client-server communication such that OAB downloads aren't happening.