How to index Outlook and Exchange messages with dtSearch

Last Reviewed: March 12, 2018

Article: DTS0130

Applies to: dtSearch 7.77 and later

How to index

dtSearch includes three ways to index Outlook or Exchange messages, contacts, tasks, appointments, and notes:

(A) dtSearch can index "live" content in your Outlook profile (the PST files you are currently using),

(B) dtSearch can extract PST or Exchange data to a folder tree of MSG files for indexing, and

(C) dtSearch can index Outlook PST and OST message archives directly (without using Outlook).

Each message item, including all attachments, is indexed as a single document.  Attachments are appended to the message body.  Alternatively, you can configure dtSearch to treat each attachment as a separate document.  For information on this option, see How to index attachments separately from email messages.

After a search, you can view retrieved items in dtSearch, with hits highlighted.  Click Edit > Copy File(s) in dtSearch Desktop to copy all or selected messages from search results to a folder.  When you index using option (A) or (B), you can also open retrieved Outlook messages and other items in Outlook.  To open an item in Outlook, click on the item in dtSearch and then press F8 or click the "Launch" button on the dtSearch Desktop toolbar.

(A) Indexing Outlook messages and other information in your Outlook profile,

To index Outlook data using dtSearch, in the Update Index dialog box, click Add Outlook to add one or more Outlook folders.

dtSearch Desktop support for Outlook indexing works with 64-bit and 32-bit Outlook versions 2016 and earlier, back to Outlook 2010.  Outlook must be installed for Outlook indexing to work because dtSearch uses the Outlook program to access Outlook data.  

dtSearch Desktop includes both a 32-bit indexer and a 64-bit indexer.  Use the 64-bit dtSearch indexer if you have 64-bit Outlook and use the 32-bit dtSearch indexer if you have 32-bit Outlook.

(B) Bulk indexing of PST or Exchange data

For archiving and forensic applications, you can also extract PST and Exchange data to .MSG files.  dtSearch can index .MSG files without going through MAPI, Outlook, or Exchange, so converting the data to .MSG eliminates the need for the data to be attached to a profile or for Outlook to be installed when indexing and searching.   The converted .MSG files will include all properties of the original Outlook item, including any attachments.

To perform bulk conversion of PST and Exchange data, dtSearch includes a command-line tool, mapitool.exe.  For documentation on mapitool, see mapitool.html in the dtSearch BIN folder.  To convert the data, mapitool.exe relies on Outlook, so Outlook must be installed at the time the conversion is done.  Once the data is converted, dtSearch can index the generated .MSG files without Outlook.

Converted .MSG files can be indexed and searched in any dtSearch product, including dtSearch Web, just like any other supported document format.

Outlook Express. The above procedure applies to Outlook only, not Outlook Express. Outlook Express messages are stored in archives with a .DBX extension, and dtSearch can index these files like any other files.

(C) Direct indexing of PST and OST files

dtSearch can also index PST and OST files directly, without using Outlook.  Because Outlook locks the PST or OST file that is currently in use, this will not work with a PST or OST file that you are actively using in Outlook, and is primarily for use in situations where archived or forensically-obtained PST or OST files are being searched.

To index PST or OST files, simply add them to the index like other files or folders.  


(1) PST files are relatively slow to open due to their structure, so opening documents after a search will be slower with this indexing method than with options (A) or (B) above.  

(2) OST support is available beginning with dtSearch version 7.77.  Microsoft has not officially documented the OST file format specification, so this support is based on unofficial non-Microsoft information about the OST file format.

Message Properties Indexed

For information on supported message properties, please see What file formats does dtSearch support?

Troubleshooting Outlook Indexing

A crash occurs during indexing or searching Outlook messages

Please see this Microsoft article for an Outlook patch to correct an Outlook bug that can cause this:

April 14, 2015 update for Outlook 2010 (KB2965295)

Message: "Outlook Application could not initialize"

Message: "Outlook Error 800401f3: Invalid Class String"

These errors can indicate that scripting support is disabled or damaged in your Outlook installation.  If Outlook was installed without scripting support, the following steps will fix the problem:

(1) Click Start > Settings > Control Panel > Add/Remove Programs

(2) Locate Microsoft Office in the list of installed programs

(3) Click the "Change" button

(4) Click "Add or Remove Features" and then click "Next"

(5) Check the box "Choose advanced customization of applications" and then click "Next"

(6) Click the box next to "Microsoft Office Outlook" and select "Run all from my computer" from the drop-down list that appears.

(7) Click the "Update" button.

If Outlook was fully installed but the installation is damaged, the following steps will fix the problem:

(1) Click Start > Settings > Control Panel > Add/Remove Programs

(2) Locate Microsoft Office in the list of installed programs

(3) Click the "Change" button

(4) Click "Reinstalll or Repair" and then click "Next"

(5) Select "Detect and Repair errors in my Office installation"

(6) Click "Install"

This error can also occur if you run dtSearch as Administrator while Outlook is running as a standard user.  To prevent this from occurring, close Outlook before running dtSearch, or run both dtSearch without using "Run as Administrator".

Message: "Either there is no default mail client or the current mail client cannot fulfill the messaging request. Please run Microsoft Outlook and set it as the default mail client."

Possible causes for this are:

(1) Outlook is not installed, or Outlook is installed without the messaging components.  To correct this, run the Microsoft Office installer from "Add or remove programs" and make sure that Outlook is installed with the messaging components.

(2) You are using the 32-bit version of mapitool with the 64-bit version of Outlook, or the 64-bit version of mapitool with the 32-bit version of Outlook, or (3) Outlook is not the default email client.  To see which version of Office you have, run Outlook and click File > Account > About Outlook.

(3) Outlook is installed but is not the default mail client.  Outlook indexing will not work unless Outlook is your "default" mail client. (You can still have other email programs installed, but Outlook has to be the default.) There are two places this setting has to be changed:

(1) In Outlook, click Tools > Options > Other, and check the box, "Make Outlook the default program for E-mail"

(2) In Internet Explorer, click Tools > Options > Programs, and make Outlook the default program for email.

"The Server is Unavailable"
No messages or items found during indexing

If you have multiple Outlook profiles, either (1) Outlook must be set to always use one of the profiles, without prompting, or (2) Outlook must already be running when dtSearch is started. The reason for this is that dtSearch may not be able to prompt you for the profile to use during indexing (for example, during an unattended indexing job). To set an Outlook profile as your default,

(1) Click Start > Settings > Control Panel > Mail

(2) Click Show Profiles

(3) Select the profile to use with dtSearch from the list at the end of the dialog box, and

(4) select Always use this profile.

(There is a checkbox in the "Select Profile" dialog box that appears when you start Outlook that supposedly does this, but it seems to have no effect.)

The ScanPST Inbox Repair Utility

The ScanPST utility is a Microsoft tool for fixing problems with Outlook .PST and .OST files. For information on using this tool, please see:

Repair Outlook Data Files (.pst and .ost) (Office 2013)

Repair Outlook Data Files (.pst and .ost) (Office 2010)