You may experience one of the following symptoms:

  • Partial or no search results are returned.
  • Items that you expect to appear based on your search criteria are not displayed.

In this case, the indexing of your Microsoft Windows and Microsoft Office system data files (the search catalog) may not be complete.

To fix the issue you need to rebuild the search catalog, which restarts the indexing of your data files. The search catalog is a file where all of your Outlook and Microsoft Windows items (data files) are indexed.
To rebuild your search catalog, do the following for your Outlook version:

Outlook for Windows:

Important: Rebuilding of the search catalog may take up to several hours and it may stop temporarily if you use the computer actively. Your computer may be working slowly during rebuilding.

    1. Exit Outlook.
    2. In Microsoft Windows, click the Start button, and then click Control Panel.
    3. Do one of the following:
      • Windows Vista  
        Click System Maintenance, and then click Indexing Options.
        Note: In Classic view, double-click Indexing Options.
      • Windows 7/8/10
        Switch to view by small/large icons and double-click Indexing Options.
    4. Click Modify, select the checkboxes for the locations you want to index, and then click Ok.
    5. Click Advanced.

    6. Click Rebuild.

    7. Restart Outlook.

Note: if outlook throws an error message that something went wrong and your search couldn't be completed, the following key can be added to unbind the time threshold of 5 seconds when the outlook client is querying the Exchange server and waiting for a response.

The fix is to add DWORD in the registry:
Name: DisableServerAssistedSearch
Value: 1

Important:  The Outlook Quick search has a default limitation for the displayed number of items that vary depending on the Outlook version: Outlook 2010 - 200 results; Outlook 2013 and later return 250 results. If you would like to increase the number of displayed results make sure that the Outlook client runs in the cached mode and use one of the options below:

Option 1 (Disables the limitation completely):

1. Click File > Options > Search.
2. Under Results, clear the Improve search speed by limiting the number of results shown check box.

Option 2 (Allows you to configure the exact number of items to be displayed):

Update the following Value in the Registry:

Key: HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Outlook\Search
Value name: SearchResultsCap
Value type: REG_DWORD
Value: 0 to 4294967295 (decimal)

If the value is set to 0, all results are returned (the same Option 1).
If the value is missing, the Outlook mail client will display the default number of results.
If the value is set to any other value, that amount of results are being returned.

Outlook for Mac:

If you do not see any search results coming up in your Outlook, you may want to rebuild search index on your machine. This can be done through the Spotlight control panel or through Terminal. Note that your computer may be working slowly during reindexing.

Important: If you've upgraded to macOS 10.15 Catalina, please use the second option and manually enable indexing. 

Rebuilding index using Spotlight search

To start reindexing process of an entire drive follow these steps:

    1. Exit Outlook.
    2. Launch System Preferences from the Apple menu.
    3. Under Personal click on Spotlight.
    4. Switch to the Privacy tab. Click the + button and choose your Macintosh drive (and other drives if necessary) or simply drag it and drop into the Spotlight window.
    5. Now select the drive(s) you just added and click the - button to remove it from the list.Z
    6. Spotlight will start indexing of the removed drive automatically. To view the remaining time click on the Search button.

Note: if a drive is left in the Privacy list, it will be excluded from Spotlight indexing completely. You will not be able to get any search results.

Rebuilding index using Terminal 

It is also possible to rebuild the indexing using the Terminal. To manually reindex Spotlight via Terminal follow these steps:

  1. Double-click the Hard Drive icon and navigate to Applications > Utilities.
  2. In the Utilities folder, double-click one Terminal
  3. In Terminal, type: sudo mdutil -E /

Note: You will be prompted to enter your password from the device.


Important: OutlookSearchRepair is only applied to MacOS and not supported with MacOS Mojave 10.14 and higher versions.

Sometimes, Spotlight doesn't seem to process a reindexing request (nothing happens after you remove a drive from Privacy). In this case, use OutlookSearchRepair app. This app is designed for reindexing in Outlook 2016

How to use:

  1. Open OutlookSearchRepair utility
  2. Follow the instructions and remove any duplicate installations of Outlook if more than one installation is detected. If no duplicates are detected, you can skip to step 3 below. After removing duplicate Outlook installations, a restart is required. Once your system is restarted, the Outlook Search Repair utility may reopen. Quit and relaunch the Outlook Search Repair if it reopens upon restarting.
  3. Click the Reindex button. The Outlook Search Repair Utility will show Reindexing, please wait… while it works. This process can take up to an hour or longer depending on the size of your Outlook profile. Outlook does not need to be open while the repair occurs. Spotlight search will be slower and might not be complete while the index is repaired. Once the repair is completed, you’ll see: Done! Reindexing has completed! You can quit Outlook Search Repair Utility once you see that message.

Note: in some cases, search feature does not work in Outlook for Mac if the mailbox has a folder with '/' in its name. In order for search feature to function, remove '/' sign or rename the folder.