You need to find an email but only remember the name of a file attached to it. Searching by sender or subject does not work in this case. Outlook has a specific search syntax for locating messages based on their attachments. This article explains how to use attachment name searches in both the desktop app and Outlook on the web.
Key Takeaways: Search Outlook by Attachment Name
- Search box with ‘attachment:’ keyword: Type this operator followed by the file name to filter your mailbox for specific attachments.
- Windows Search Index: Must be active and healthy for the desktop app’s instant search to return complete results.
- Outlook on the web search filters: Use the ‘Has attachments’ filter and then type the file name in the main search box for web mail.
Understanding Outlook’s Attachment Search Feature
Outlook can search inside email attachments for text content if you have the correct tools installed. However, searching for emails based solely on the attachment’s file name is a core function. It relies on the email’s metadata, which stores the name of any attached file.
For the Outlook desktop app on Windows, this search depends on the Windows Search service. The service builds an index of your Outlook data to deliver fast results. If the index is incomplete or disabled, your searches may be slow or return no items. Outlook on the web and the mobile apps use Microsoft’s cloud servers to perform the search instantly.
Search Syntax and Operators
The primary operator for this task is ‘attachment:’ followed by the file name. You can use a full name like ‘Q4-Report.pdf’ or a partial name with a wildcard, such as ‘report’. The search is not case-sensitive. You can combine this operator with others, like ‘from:’ or ‘subject:’, to narrow results further.
Steps to Search by Attachment Name in Outlook Desktop
Use these steps in the Outlook application for Windows or Mac. The process is similar for both, but the search box location differs slightly.
- Click the search box
In the main Outlook window, click inside the search box above your message list. On Windows, you can also press Ctrl+E to place your cursor there instantly. - Enter the attachment search query
Type the keyword ‘attachment:’ followed immediately by the file name. For example, typeattachment:budget.xlsx. For a partial name, typeattachment:invoiceto find all files with ‘invoice’ in their name. - Review and filter the results
Outlook displays all emails with matching attachments. Use the Search Tools tab that appears to filter by date, folder, or other criteria. Click a result to open the email and verify the attachment.
Searching in Outlook on the Web
The web version at Outlook.com or via Microsoft 365 has a slightly different interface but offers the same capability.
- Navigate to your mailbox and click search
Open Outlook in your browser and sign in. Click the search box at the top of the page that says ‘Search mail and people’. - Apply the attachment filter first
Click the filter icon in the search box. From the dropdown, select ‘Has attachments’. This action adds a filter to your search. - Type the file name
In the main search box, now type the name of the attachment file. You do not need to use the ‘attachment:’ keyword here. Press Enter to see all messages with attachments that match the name.
Common Mistakes and Limitations
Search Returns No Results When Emails Exist
If you know an email with the attachment exists but search finds nothing, the Windows Search index may be faulty. Open the Windows Indexing Options via Control Panel. Click Modify, then ensure your Outlook data file location is checked. Click Advanced and select Rebuild to reset the index. This process can take time.
Searching for Specific File Types Only
The ‘attachment:’ operator searches for file names, not file types. To find all PDFs, you must search for the ‘.pdf’ extension. Use a query like attachment:.pdf. Be aware that some files may not have an extension listed in the email metadata.
Attachments Inside Archived or PST Files
Outlook only searches data files currently added to your profile and online mailboxes. If the email is in an offline archive PST file not open in Outlook, it will not appear in results. Add the PST file to your profile via File > Account Settings > Account Settings > Data Files tab.
Desktop Search vs Web Search Comparison
| Item | Outlook Desktop App | Outlook on the Web |
|---|---|---|
| Primary Search Method | Use ‘attachment:’ keyword in search box | Use ‘Has attachments’ filter then type file name |
| Speed Dependency | Local Windows Search index health | Microsoft server speed and connection |
| Advanced Query Syntax | Supports Boolean operators like AND, OR | Limited to basic filters and text |
| Search Scope Control | Can search current folder, all mail, or subfolders | Typically searches all folders by default |
| Offline Search Capability | Yes, if cached mailbox data is indexed | No, requires an active internet connection |
You can now quickly locate any email by recalling the name of its attached file. Remember the core ‘attachment:’ operator for the desktop app and the filter-first method for the web version. For a faster search on Windows, keep your Outlook data files in the indexed locations list. Try combining the attachment search with a date range using the ‘received:’ operator to pinpoint very old messages.