Exchange mailbox restore fails at the beginning with the error “Could not open message store” (4033066)

When on Mailbox Restore, the selected destination is “Restore to original location”.

The restore fails at the beginning (on step “Prepare mail store”) with an error “Could not open message store”.

Exchange 2016 has the "MAPI over HTTP" option enabled by default. This causes the restore to fail. For more information: Configure MAPI over HTTP.

1. Check which account is used for restore operations:
   1. Remember the profile name which is selected in the “Profile” dropdown list in the Restore Wizard.
   2. Open Mail applet in Control Panel
   3. Сlick on “Show Profiles…” 
   4. Select the needed profile and click “Properties”
   5. Click on “E-mail Accounts…”
   6. The needed value will be in the list on the “E-mail” tab in the opened dialog box.

2. Grant “Full Access” permissions for the destination mailbox. Perform the following steps to do this:

1. Open the Exchange Administrative Center in your browser (https://<your_server_name>/ecp) and log on as an administrator.
2. Open the “Recipients” – “Mailboxes” view, find the account that you want to restore (use as a restore destination) and open its properties.
3. Open “mailbox delegation”, add the mailbox which you use for restore operations (see step 1) into the “Full Access” list and click the “Save” button.
4. Re-start (exit and run again) Outlook using the selected mail profile (you can select which mail profile is used by Outlook in dialog from step 1-d); ensure that the mailbox appears here. It might take some time until Outlook shows the added mailbox. You can also try to add the needed mailbox manually in the mail account settings (click on the “Change…” button in dialog from step 1-f)

NOTE: please ensure you can open the destination mailbox in Outlook after these actions have been performed. If this still fails and Outlook shows errors like “Cannot display the folder. Microsoft Outlook cannot access the specified folder location. The operation failed. An object cannot be found”, you may need to re-create the mail profile to force Outlook update its configuration.

         3. When the mailbox has appeared in Outlook, run the restore again.