What is Cached Exchange Mode in Outlook?

Do you know that Outlook users can access their Exchange account and utilize Outlook even in offline scenarios? Yes. Cached Exchange Mode is a feature in Microsoft Outlook that allows users to use Outlook without internet connectivity. The present blog has thoroughly explored this feature of Outlook. It highlights the advantages of Outlook Cached Mode and provides steps to configure it within Outlook.

  Download Now Purchase Now

There are two Methods to establish a connection between Outlook and an Exchange account:

1. Online Mode
2. Cached Exchange Mode (Offline mode)

Online Mode establishes a direct connection to an Exchange server. It uses data directly from the Server and requires an internet connection. While Cached Exchange Mode in Outlook serves as the default mode for Microsoft Exchange and Microsoft 365 server accounts. This mode is particularly advantageous in case of unstable internet connection or frequent connectivity problems. Thus, it helps improve the performance and responsiveness of the email client. 

When Outlook Cached Exchange mode is enabled, it creates a duplicate copy of your mailbox data. This copy is stored on the computer’s hard drive. Outlook then operates from this local copy of the mailbox, along with an Offline Address Book (OAB).

Outlook Cache Mode vs Online Mode

Cached Exchange Mode and Online Mode differ in terms of the range of features they offer. These are scenarios of how Online Mode and Cache Mode differ:

Feature	Cached Exchange Mode	Online Mode
Data Access	Uses a local copy of mailbox data.	Direct connection to the Exchange server for data access.
Performance	Faster and more responsive as it accesses local data.	Can be slower, especially on slower or unreliable internet connections.
Offline Access	Access and work with your mailbox data offline	Need a continuous internet connection.
Synchronization	Synchronizes changes made offline with the server when back online.	Changes are made directly on the server in real time.
Storage	Requires additional local storage for the cached mailbox data.	Doesn’t consume additional local storage as it relies on server access.
Network Dependency	Reduced dependence on network speed and stability	Heavily dependent on network speed and stability

Advantages of Using Cached Exchange Mode

Here are the advantages of Outlook Cached Mode:

1. Users can perform tasks such as accessing email, even in the absence of Internet connectivity.
2. Besides storing the primary mailbox, Outlook also maintains a duplicate of the cached mode offline Global Address Book.
3. Finding files and information in offline storage (OST) files becomes easier.
4. Users who frequently work offline or without an internet connection.
5. This mode proves particularly beneficial for users who have high-latency connections (greater than 500 ms) to the Exchange servers.
6. OST files perform better than online files, in radio-frequency-based connections.

Restrictions of Outlook Cached Exchange Mode

Apart from the advantages, there are some limitations of the Outlook Cache Mode too:

• Storing a copy of the Exchange mailbox on your computer requires a significant amount of disk space.
• Outlook Offline mode causes delays in updating mailbox data.
• It creates an OST file, inaccessible if your Exchange server experiences downtime.
• Restrict certain functionalities, such as public folder access.

In the following section, let us see how to check if Outlook is running in Online mode or Offline mode.

Is Cached Exchange Mode in Outlook Enabled?

To know whether Outlook is running in Offline Cache mode or Online mode, follow the steps:

1. Launch Outlook in your system.
2. Go to File and then click on Account Settings.
3. From the drop-down menu, again choose Account Settings.
4. Now, select the desired email you want to check for and click Change.

5. Change Account window opens. Click on More Settings.

6. Go to the Advanced tab, in Microsoft Exchange Window.
7. There, find the ‘Use Cached Exchange Mode’ option. If it is selected, Outlook is running in Offline mode, otherwise in Online mode.

So, this is how you can check if Cached Mode is enabled. Therefore, it’s also important to know how to turn on and turn off Outlook Cached Mode.

To enable/disable Offline Cached Mode, follow the above-mentioned process and further follow the steps below:

• Turn On– Check the ‘Use Cached Exchange Mode’ 
• Turn Off– Uncheck the ‘Use Cached Exchange Mode’

Furthermore, to enable shared mailbox Cached Mode, check Download Shared Folders. Also, check the Download Public Folder Favorites checkbox to enable cached mode for Public folder favorites.

Note: When cached mode is enabled, Outlook downloads these shared folders and public folders to the local cache.

When Cached Exchange Mode will be Unavailable?

Outlook Cached Mode will not be available in certain cases. They are:

• If the email account in Outlook is not set up as an Exchange account.
• Older versions of Outlook may not support Offline Cache mode, such as Outlook 2000.
• If you are using Windows Server with Microsoft Terminal installed.
• Not having sufficient permissions to access shared folders associated with the Exchange account.

Since Cached Exchange Mode is enabled in Outlook, it will generate an OST (Offline Storage Table) file. This OST file is a local copy of the user’s Exchange mailbox. Therefore, it serves as a backup in the event of an Exchange server crash, virus or malware infection, or Outlook crash. However, the OST file may become corrupted or inaccessible if any of these events occur. As a result, Outlook will fail to synchronize with the Exchange server and retrieve new emails.

Recover Data from Corrupt/Inaccessible OST File

In case, the OST file is corrupt/damaged/inaccessible, Outlook might encounter several errors OST Synchronization Error. Oversized OST files can be a reason for such errors. To fix such Outlook errors, you need to convert OST files to PST. Further, store PST files for future reference and free up the disk storage. Once disk space is empty you can again enjoy Outlook Cached Exchange Mode.

The best way to convert OST to PST is using DRS OST to PST Converter. It is a remarkable tool that efficiently converts Outlook OST files to PST while preserving their original content. Besides PST, this utility allows users to export OST files to different file formats and email clients. Moreover, with its advanced features, this tool ensures a seamless and precise conversion process. Some of its noteworthy features include removing duplicates, specific migration, etc. Furthermore, it intends to provide 100% accurate results and maintains the utmost privacy of your OST file data.

Conclusion

Hence, this was a comprehensive blog about what is Cached Exchange Mode in MS Outlook. We have tried to cover all aspects of this outlook feature including its advantages and disadvantages. Furthermore, you get to know the process to enable/disable Cached Mode on Outlook. Hope, you now better understand what it is and how is it different from the Online mode in Outlook.

Frequently Asked Questions