For example, a staff member changes surnames and the help desk updates their Active Directory account with the new name.The staff member may notice that when the address book is viewed in Outlook their name remains unchanged, and may do so for 24-48 hours.This situation however is extremely rare since the default maintenance time on Exchange is at AM and updates and downloads are usually performed during working hours.*** NOTE: The GAL is essentially a real-time / online representation of AD Objects that are Mail Enabled for Microsoft Exchange *** The GAL contains information for all email enabled users, Distribution Groups, and Shared Mailboxes and Exchange Resource Mailboxes.Eventually I got to the conclusion that what the above text is trying to tell us is that, by default, Exchange updates the OAB every 8 hours.If I look at my environment, I can see this is indeed the case: For organizations where recipients change at a considerable rate, this might not be ideal.
Because of this, a new user may not be visible in the address book, or changes to a user’s name, address, etc.However sometimes in large complex organisations we have a situation where a new joiner joins and their colleagues want to email them immediately, but they don’t appear in Outlook for them so they call the Helpdesk “Why isn’t Joe Bloggs in the GAL??” Well, the truth of the matter is that our new joiner Joe is in fact , an update to the Address Book won’t become available to the user until about 48 hours after the change.After discovering a DC with the GAL, it appears that Outlook never tries to query for GAL servers again. @dstranathan I think I'm getting closer to an answer.I assume it does this by searching for _ldap._loc SVR records in DNS or it does it via AD CAS Auto Discover foo that Im unaware of. Through this post, I found what looks to be the Offline Address Book .plist file here: /Users/isaachalvorson/Library/Group Containers/UBF8T346G9.