Exchange 2016 offline address list not updating
Rather than waiting 24 hours for Outlook to update the Offline Address Book on its own, you can force an update via the Send/Receive menu button.
Use the Update-Offline Address Book cmdlet to update the offline address books (OABs) used by Microsoft Outlook clients.Remember, if you are looking at the Global Address List in Outlook then you are NOT looking at the Servers Global Address List*.If you are using Outlook 2003 or 2007 you may be in "Cached Mode", and you are looking at a copy called the "Offline address book" This only gets updated Every 24 hours, and the copy on the server only gets updated every 24 hours at (by default).For more information, see the "Add a role to a role group" section in the topic, Manage role groups.parameter specifies the domain controller that's used by this cmdlet to read data from or write data to Active Directory.Therefore, not all the information in the GAL is available in the offline address book.
The following information in the GAL isn’t available in the offline address book: Outlook must be able to access Exchange to obtain this information.
If the update mechanism appears to be broken for you, it could be because of a corruption in your OAB or in your mail profile.
In that case, you can completely reset it by deleting the files making up the OAB or by recreating your mail profile.
Although all parameters for this cmdlet are listed in this topic, you may not have access to some parameters if they're not included in the permissions assigned to you.
To see what permissions you need, see the "Offline address books" entry in the Email address and address book permissions topic.
The offline address book contains the properties of a user, such as email addresses, that Microsoft Outlook requires to send an email message and display information about the sender.