Exchange global address book not updating
You can disable the option “Download changes since last Send/Receive” to make sure you get a complete fresh copy of the OAB but this could take longer to download.
In Outlook 2010 and previous, it is recommended to leave the option “Full Details” enabled.
Is there any way I can force a manual update of the Offline Address Book (OAB) in Outlook or reset it completely otherwise?
In general, Outlook will automatically update the Offline Address Book (OAB) for Exchange accounts once every 24 hours.
You can use this switch to view the changes that would occur without actually applying those changes.
To see the input types that this cmdlet accepts, see Cmdlet Input and Output Types (https://go.microsoft.com/fwlink/p/? If the Input Type field for a cmdlet is blank, the cmdlet doesn't accept input data.
This delay between an email account being create and being listed can cause organisational issue, like a users being unable to find the email address for a new staff member.In that case, you can completely reset it by deleting the files making up the OAB or by recreating your mail profile.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.The Identity parameter specifies the GUID, distinguished name (DN), or OAB name that represents a specific OAB.You can also include the path by using the format Server\Offline Address Book Name.