Outlook 2016 global address list not updating cached mode
I wrote this for my IT Dept for that same problem: ISSUE: You have an Outlook client in cached mode that is not updating the OAB (Offline Address Book). Next time you start Outlook it will re-download the address book and create new OAB files.The problem was the oab files got corrupt and would not catch new updates.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".When I disable cached mode and restart outlook I see the new address fine.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.
Your Exchange admin should be able to configure the time interval between updates for your Offline address book downloads.
If it continues to happen, try excluding these oab files from your anti-virus scanner.
Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system.
Interestingly enough, I open the Global Address List now, and it is non-populating.
I go back to the Outlook connectivity test feature, click "Connection Status", and click "Reconnect". I turn on Cached Exchange mode and when I open the address book this time, the GAL is populated. I tried to search for a name that I knew was in the address book Strangely, although my GAL is empty, there is a result. CN=[user name], right click, then select "Properties" 4.