Exchange Recovery Mode:

Microsoft Outlook 2003 and newer versions introduce a new feature called Cached Exchange Mode, which is actually an improved version of offline folders in Outlook older versions. Cached Exchange Mode provides many functions to make the synchronization and offline operations efficiently and conveniently. One of them is Exchange Recovery Mode.

When the Exchange server, database, or mailbox associating with the offline folder (.ost) file is reset, or there is an inconsistency between the Exchange mailbox and the OST file, then if you are running Outlook 2002 or older versions, or running Outlook 2003 and newer versions but have Cached Exchange Mode disabled, and choose to work online, then Outlook will create a new OST file for the new mailbox. The old OST file will not be deleted, but you cannot access the data in it. Later when the original mailbox is available again, you will be able to access the data in the old OST file, but those in the new OST file will be inaccessible again. If you need to access the data in both OST files, you need to edit the Outlook profiles manually to redirect them to the corresponding OST files, which is very inconvenient.

However, if you are using Outlook 2003 and later versions, and the Cached Exchange Mode is enabled, then you will see the following warning message when your Exchange mailbox is reset or inconsistent:

Exchange is currently in recovery mode. You can either connect to your Exchange server using the network, work offline, or cancel this logon.

which indicates Outlook and Exchange are currently in Exchange Recovery Mode.

When in Exchange Recovery Mode, you have two options:

  • Offline mode. If you select Work Offline, you can access the data in your old OST file, but not to the Exchange server. The old OST file is still accessible in offline mode.
  • Online mode. If you select Connect, you can access the Exchange server, but not to the old OST file. If you want to access data in the old OST file, you can exit Outlook and start again in Offline mode.

Thus, by selecting different options, you can access the old OST file or new mailbox on the Exchange server selectively.

In Exchange Recovery Mode, you can convert the old OST file into a PST file to migrate its data to the new Exchange mailbox.

If later the old Exchange mailbox associating with the old OST file is available again, then by selecting Connect, you will exit Exchange Recovery Mode automatically.

However, if the mailbox is unavailable permanently, or it is inconsistent with the old OST file due to the OST file corruption, then how to exit Exchange Recovery Mode and make Outlook work normally again? Below is the answer.

Exit Exchange Recovery Mode and Work Normally Again:

If the Exchange mailbox is not available for ever, or it is inconsistent with the old OST file due to file corruption, then please do as follows to exit Exchange Recovery Mode and let Outlook work normally again:

  1. Close Outlook.
  2. Find the old OST file.
  3. Rescue the offline data in the old OST file with DataNumen Exchange Recovery.
  4. Back up the old OST file.
  5. Turn off the Cached Exchange Mode:
    1. Launch Outlook.
    2. On the Tools menu, select E-Mail Accounts.
    3. Click View or change existing e-mail accounts, then proceed by clicking Next.
    4. From the list Outlook processes e-mail for these accounts in the following order, select the Exchange Server e-mail account, and then hit Change.
    5. Under the Microsoft Exchange Server section, uncheck the Use Cached Exchange Mode option.
    6. Close Outlook.
  6. Rename or delete the old OST file.
  7. Turn on the Cached Exchange Mode. Similar to step 5, except that you need to check the Use Cached Exchange Mode option.
  8. Start Outlook, then connect to your Exchange mailbox to create a new OST file and resynchronize it with your mailbox. You will now exit Exchange Recovery Mode.