The other day I was troubleshooting an issue where users were not able to download the Offline Address Book (OAB).After some troubleshooting steps, I ran the Outlook Auto Configuration Test and noticed that the URL for the OAB was not listed: To further test the OAB, beside manually downloading it in Outlook, you can write down the OAB URL, paste it into the address box in Windows Internet Explorer, add /to the end of the path, and then press Enter.Synchronizing your Outlook (cached) address book with the Global Address book may fix these discrepancies.
This means that in the worst possible scenario, an update to the Address Book won’t become available to the user until 48 hours after the change.
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.
Exchange 2013 has gone through an evolution in the way the Offline Address Book is generated and maintained.
While most of the changes are advantageous, I ran into a chink in the armor while working with a customer who was having an issue with Exchange 2013 DAG replication.
When you have Cached Exchange Mode enabled, Outlook by will by default cache the main Global Address List as well.
This is called the Offline Address Book and is being generated on the Exchange server.We were having issues with their Exchange 2013 servers and one node would crash or lose connection and break the DAG replication.This would leave the source database mounted and the destination (the second database copy) would end up in a “Failed and Suspended” state.Due to various synching schedules, it can take up to 48 hours before you could actually see a change in Outlook after a modification has been made on the Exchange server or in Active Directory.In this guide, the relevant timings are explained and instructions are given in how you can directly force an update and resync, which can be very handy when troubleshooting or when you work in an Exchange environment which sees a lot of user mailbox mutations.Even though Outlook is the last in the chain, it is often the first level where the troubleshooting takes place as usually this is where the request is coming from.