A common reason for this is the offline address book (OAB) schedules that are in place for the environment.
Consider the following process: So it is easy to understand why changes may not appear in the address book for cached-mode Outlook users for 24-48 hours after the change is actually made.
migrating domains, we are simply raising the domain functioning level with newer versions of Windows Server 2012 R2.
Outlook 2016 (and presumably Outlook 2011) seem to set their LDAP GAL Directory server one time (at account set up time or initial launch).
This document seeks to address and clarify the small misunderstanding surrounding the GAL (Global Address List) and the OAB (Offline Address Book).
Quite often all Administrators, even Exchange Administrators simply refer to the users they see in the Address section of Outlook casually as the GAL for ease of reference, but really more often than not, you are looking at the OAB.
In Exchange 2013 (at least in CU9 at the time of writing this) we still see this property but it is no longer used: Maybe it is because English is not my first language, but it took me a while to understand exactly what the above means...A delay for changes appearing in the OAB may be perfectly acceptable to some organizations.And additional load from OAB generation and distribution cycles running more frequently may be undesirable to some administrators.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.