You need to find information contained within a file attached to an email, but Outlook’s standard search only looks at the email body. This happens because Outlook relies on the Windows Search index to read attachment content. This article explains how to enable and use this feature to find text inside PDFs, Word documents, and other common file types.
Key Takeaways: Searching Inside Outlook Attachments
- Windows Search Indexing Options: You must enable indexing of file contents for Outlook to search inside attachments.
- Search Box > Search Tools > Search Options: This menu in Outlook controls whether attachment content is included in your queries.
- Attachment: operator: Use this search filter in the Outlook search box to specifically look for text within attached files.
How Outlook Searches Attachment Content
Outlook does not open and read attachments directly when you search. Instead, it depends on the Windows Search service. This service runs in the background, creating an index of words found inside files on your computer, including those saved from emails.
For this to work, the file types must be supported by Windows Search filters. Common formats like .pdf, .docx, .xlsx, .pptx, and .txt are typically indexed. The email containing the attachment must also be stored in an indexed location, such as a local Outlook Data File or a mailbox using Cached Exchange Mode.
Prerequisites for Attachment Search
Your system must meet a few requirements. First, Windows Search must be running. Second, the index must be configured to include the file contents of your attachments, not just their names. Finally, the Outlook search option for attachments must be turned on. If any of these are missing, your searches will only scan email subjects and bodies.
Steps to Enable and Use Attachment Search
Follow these steps to configure Windows and Outlook for searching inside email attachments.
- Verify Windows Search Index Settings
Open the Start menu and type “Indexing Options”. Select the Control Panel app. In the window, click Modify. Ensure your Outlook data location is listed. For most users, this is under C:\Users\[YourName]\AppData\Local\Microsoft\Outlook. Also confirm that the file types you need are set to index content. - Enable Attachment Searching in Outlook
Open Outlook and click in the search box at the top of the message list. A Search tab will appear on the ribbon. Click Search Tools, then select Search Options. In the Outlook Options dialog, go to Search. Under the Sources heading, check the box for Include results from file contents. - Perform a Content Search
Click in the search box in your mail folder. Type the word or phrase you want to find. Outlook will now return emails where that text appears either in the message body or inside an attached file. The results will show a snippet of the matching text. - Use the Attachment: Search Operator
For a more precise search, use the attachment: operator. In the search box, type attachment: followed by your search term without a space, like attachment:budget. This tells Outlook to only look for that text within attached files, ignoring the email body text.
Common Mistakes and Limitations
Search Returns No Attachment Results
If searches do not find text inside attachments, the Windows index may be incomplete. Open Indexing Options again and click Advanced. Click Rebuild to delete and recreate the search index. This process can take hours but is often necessary after a major Windows update or if the index is corrupted.
Outlook Online Mode or Web App
The attachment content search feature requires a local index. If you use Outlook in Online Mode without a local cache, or if you use Outlook on the web, you cannot search inside attachments. The search will only look at file names. You must use Cached Exchange Mode for this feature to work.
Unsupported File Types
Windows Search cannot index the contents of every file. Images, executable files, and some proprietary formats will not be searched. The text inside a scanned PDF saved as an image will not be found unless you use optical character recognition software first. Check the list of indexed file types in Indexing Options > Advanced.
Search Methods for Different Attachment Types
| Item | Standard Text Documents | Scanned PDFs or Images |
|---|---|---|
| Search Method | Use standard search box or attachment: operator | File name search only; content search not possible |
| Required Setup | Windows Search index with file contents enabled | No special setup; relies on OCR software outside Outlook |
| Example Query | attachment:Q4report | filename:scan.pdf |
| Indexing Time | Automatic after file is received and saved | Not applicable |
You can now locate specific information buried within email attachments. Remember to rebuild the Windows Search index if results seem outdated. For advanced searching, combine the attachment: operator with other filters like from: or received:. This lets you narrow results to attachments from a specific sender within a date range.