What is Cached Exchange Mode in Outlook?

Aftab Alam Aftab Alam Updated On - 10 Oct 2019

Cached Exchange Mode is one of the two modes to connect the Outlook application with an Exchange account. The other one is Online Mode. The cached mode has a job of keeping a local copy of the user’s exchange mailbox stored on the hard drive in the form of an OST file. While the Cached mode is enabled in Outlook, the Outlook client will check the OST file for all the information and searches, and another process will constantly update the mail and synchronize it will open the cached file.

The cached Exchange mode provides following benefits to the user –

  1. Apart from primary mailbox, cached mode keeps a copy of Offline Global Address Book (GAL).
  2. A user can make changes in the mailbox like accessing emails and saving drafts even when the Internet is down.
  3. It is useful for high latency connections.
  4. Searching files and information is quite easy in offline storage (OST) files.
  5. In satellite and radio-frequency based connections, OST file works much better than the online files.

Difference between Cached Exchange Mode and Online Mode –

  1. Cached Exchange Mode requires a lot of disk space in comparison to Online Mode.
  2. The number of features in Cached Exchange Mode and Online Mode is different.
  3. An index can be prepared by searching content locally in cached mode.
  4. In Cached Exchange Mode, you cannot perform searching in emails.

How to turn on Cached Exchange Mode in Microsoft Outlook application?

Cached Exchange Mode is perfectly suitable for Exchange Server users. It saves a local copy of your online mailbox to your computer. Follow the simple procedure here –

  1. Follow File>>Account Settings>>Account Settings.
  2. Select the Exchange Account and click Change.
  3. In the Offline Settings, check Use Cached Exchange Mode.
  4. Restart the Outlook application again.

How to turn off Cached Exchange Mode in Microsoft Outlook application?

If you want to turn off the Cached Exchange Mode, then follow the above-given method and uncheck the Use Cached Exchange Mode.

There is no Cached Exchange Mode in my Microsoft Outlook application –

If there is no Cached Exchange Mode option in your Outlook application, then there can be following reasons behind this scenario –

  1. Microsoft Outlook does not have an Exchange Account –
    If there is not Exchange Account included in the Microsoft Outlook, then there will be no option of Cached Exchange Mode. POP3 and IMAP accounts do not have this feature.
  2. Exchange server administrator has disabled this feature –
    An Exchange Server administrator can easily disable the feature of Cached Exchange Mode.
  3. Microsoft terminal service is installed –
    If the windows computer has Microsoft terminal installed in it, then cached Exchange Mode will not be available also.

How can I verify that Cached Exchange Mode is enabled?

Verifying the status of Cached Exchange Mode is quite easy to check. Look at the bottom of the right-hand side of Outlook application, it should say Connected to Microsoft Exchange, and an OST file is present in the computer. It means that the Cached Exchange Mode is enabled.
If Cached Exchange Mode is not enabled, then it will say Online with Microsoft Exchange.

How can I access the content from an inaccessible OST file?

A user cannot open an inaccessible file in Outlook application. If you want to recover the content of an OST file, then you should use a professional tool like Kernel for OST to PST which can recover complete OST file data. OST to PST converter is one such tool which can recover a severely corrupt OST file by converting it into PST format which is accessible in Outlook.