When you are using Outlook , Outlook or Outlook , you'll find a folder called Offline Address Books which itself holds subfolders. As Outlook an Outlook can connect to multiple Exchange servers in a single mail profile, there is an additional “Offline Address Books”. If you're using Office or Office , ensure that the latest version of Office Desktop Setup is installed. To do this, sign in to the Office portal, select.
- How to troubleshoot the Outlook Offline Address Book in an Office 365 environment
- Outlook can’t download the Offline Address Book? Try this
- The automatic sync and update schedules
- What can I do if Outlook’s Offline Address Book isn’t downloading?
- Updating Outlook manually
- Administering the offline address book in Outlook
- Offline Address Book (OAB)
- Update OAB from within Outlook
Skip to main content. Select Product Version. All Products. Microsoft Outlook has many new features and enhancements that are related to the offline address book.
How to troubleshoot the Outlook Offline Address Book in an Office 365 environment
By default, Outlook uses a cached mode configuration. Because cached mode generates an offline address book, it's important that you understand how to configure the offline address book so that it works efficiently in your Microsoft Exchange organization.
To make it easy for you to find the information that you want, this article is organized in categories in a question-and-answer format. More Information.
General information Q1: What is cached mode? A1: Cached mode is the new default configuration for Outlook.
Outlook can’t download the Offline Address Book? Try this
It provides an experience that is similar to the offline configuration in earlier versions of Outlook. When you are running in cached mode, your Exchange mailbox is synchronized to a local file an. Outlook directly accesses the. Therefore, network communication between Outlook and Exchange is significantly reduced. Q2: Why does cached mode generate an offline address book?
A2: The offline address book contains a set of all the properties of a user such as e-mail addresses and names that Outlook requires.
Instead, Outlook easily obtains this information from the local offline address book. Q3: Does the offline address book function exactly like the global address list? A3: The offline address book is a snapshot of the Active Directory directory service information that is available in the global address list.
Therefore, some information is available in the global address list that is not available in the offline address book. The offline address book does not contain the following items that are available in the global address list: Custom properties in Active Directory that an administrator has added for example, the Employee ID of each employee Organization hierarchy information Group membership information Outlook must be able to access the server to obtain this information.
Q4: What are the new offline address book features with Microsoft Exchange Server ? A4: Exchange supports a Unicode offline address book. The Unicode version is also known as Version 3a.
The automatic sync and update schedules
Exchange also supports earlier ANSI versions of the offline address book for Outlook clients with earlier versions. Exchange computers also have a filtering mechanism in place that makes sure that only those certificates that are used by Outlook for public key infrastructure PKI will be present in the offline address book. This mechanism significantly reduces the size of the offline address book from servers that are running Exchange compared to the offline address book from servers that are running earlier versions of Exchange.
Downloading and updating Q5: How frequently is the offline address book updated on the Outlook client? A5: If left constantly running, Outlook in cached mode automatically updates the offline address book on the client every 24 hours.
What can I do if Outlook’s Offline Address Book isn’t downloading?
The hour time period is measured from the time that the offline address book was last downloaded successfully. For example, if you complete an offline address book download at today, Outlook will start the offline address book download the next day at approximately Therefore, different people will receive updates at different, random times.
Note The default setting on Exchange Server and earlier versions is to generate an offline address book differential file every morning at For a change that is made in Active Directory to reach the client computer, the following events must occur: The change must be picked up by the Exchange computer that generates the offline address book files.
This can take several hours.
At worst, it can take 24 hours. This variable will be referred to as "x. This update can take several hours. This variable will be referred to as "y. It would be rare for a client to ever experience a hour delay or more unless there were some Active Directory or public folder replication issues.
Updating Outlook manually
Note For Exchange Server and later versions, the default schedule is to process the OAB every 8 hours over a period of 1 hour. OAB generation can run at different times based on resource availability. Q6: How can you tell when Outlook will try its next offline address book download? A6: Unless you notice the last time that Outlook downloaded the offline address book, you may not know when Outlook is scheduled to try the next offline address book download.
No indicator in the Outlook user interface advises you of the offline address book download schedule. Therefore, to manually force a download of the latest offline address book assuming one is available on the Exchange computeruse one of the following methods: Manually download the address book by following the steps appropriate for your versions of Outlook.
Administering the offline address book in Outlook
Click OK. If Outlook determines that either sequence ID is high as compared to the sequence ID that was downloaded, Outlook triggers the download. Q7: How frequently are the offline address book files generated on the Exchange computer? A7: By default, Exchange Server and earlier versions generate the offline address book files every morning at For Exchange Server and later versions, the default schedule is to process the OAB every 8 hours over a period of 1 hour.
Q8: How is the offline address book updated on the server and on the client? A8 : Each day, the Exchange computer generates a full offline address book and a differential file from the previous day. The Exchange computer stores the differential file and the full file for the current day and stores only the differential files for the previous days.
The following table outlines the process that Exchange and Outlook use to determine which offline address book files to download to the client. Exchange Outlook Day Full offline address book sequence number Differential sequence number Client action Offline address book result on the client 0 0 No differential.
Offline address book downloaded with sequence 2. Download differential sequence 3 and sequence 4 or offline address book sequence 4 if differential sequences 3 and 4 are greater than one-eighth the size of a full offline address book sequence 4. Q Under what conditions will Outlook perform a full offline address book download? A Outlook in cached mode will perform full offline address book download when the following conditions are true: There is no offline address book on the client computer.
Offline Address Book (OAB)
This condition may occur if Outlook has not performed an initial complete synchronization. The total size of the differential files is greater than one-eighth the size of the full offline address book. In this case, Outlook downloads the full offline address book for better performance. This condition may occur if there are lots of Active Directory objects that have a change to an attribute that is in the offline address book.
For example, phone numbers are updated with a new area code, departments are added to all users in Active Directory, and new address types are added. To modify the one-eighth rule, follow these steps.
Update OAB from within Outlook
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: How to back up and restore the registry in Windows.
Q Can I add a custom property to the offline address book? A No. You cannot add custom properties directly to the offline address book. This can cause remote procedure call RPC traffic to the server and can cause delays if these properties are published to the General tab. We recommend that you add these custom properties to alternative tabs. For more information about resolving custom properties when using Outlook, click the following article number to view the article in the Microsoft Knowledge Base: How to force Outlook or Outlook to resolve proxy addresses and custom properties in Cached Exchange Mode.
Offline address books Exchange Understanding Offline Address Books Exchange Last Updated: 20 May Was this information helpful? Yes No. Tell us what we can do to improve the article Submit. Your feedback will help us improve the support experience.
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