Outlook Find Attachments by Size: Search and Filter

Updated 9 November 2026 · Standard formula, shown below

Yes. Outlook can find messages with attachments above or below a size you specify, although the exact search syntax and filtering options vary by Outlook version. Use a search query such as hasattachments:yes larger:5MB where supported, or sort and filter messages in classic Outlook when you need a visual check.

How Outlook searches attachment size

Outlook searches messages, not standalone files in a universal attachment library. A size search returns emails whose indexed message size meets the condition; that size can include the message text, formatting, and attachment data. It is therefore a useful way to locate likely large attachments, but it may not equal the exact size of one file attached to a message.

Search operators depend on the Outlook app and the mailbox. In many versions of Outlook for Windows, search terms include hasattachments:yes and size operators such as larger: or size:. Microsoft 365 and Outlook on the web may expose similar search behavior, but the available operators can differ as Microsoft updates the service. If a query returns nothing unexpectedly, use the app’s search filters or try the size filter in classic Outlook instead.

Search for messages over a size

To look for messages larger than 5 MB, click the search box and try:

hasattachments:yes larger:5MB — asks for messages with attachments whose message size is above 5 MB.
hasattachments:yes larger:10MB — narrows the search to larger messages, if the search provider recognizes that operator.
hasattachments:yes — use this first if the size operator is unsupported, then apply a size filter or sort results.

Search scope matters. Select the relevant mailbox or folder before searching, or choose a broader scope such as all mailboxes if that option is available. A query can only return messages in the locations included in the search scope and accessible to your account. Allow time for newly received or imported mail to be indexed.

The number in a query is a threshold, not a promise that every listed attachment has that exact file size. For example, an email with two 3 MB attachments may have a total message size above 5 MB, while an attachment’s encoded email representation can be larger than the original file.

Use Outlook’s search filters

If you prefer not to type operators, start a search and look for filter controls such as Has attachments or a size-related option. The names and placement can vary between Outlook on the web, new Outlook for Windows, classic Outlook for Windows, and Outlook for Mac. Select the attachment filter first, then add a size condition if your version offers one.

Open the mailbox or folder you want to search.
Click the search field and enter a broad term, or start with the search filters.
Choose the attachment filter, if available.
Apply a size range or threshold, then review the results and open a message to verify its attachments.

Search filters are convenient for a one-time hunt. If your Outlook version does not show a size filter, that does not necessarily mean the mailbox has no large attachments; use another method below.

Find large messages in classic Outlook

Classic Outlook for Windows has a folder view that can help identify large messages visually. Open the folder, select the View tab, and choose View Settings or the available view customization control. In the sorting options, sort by Size, usually from largest to smallest. You can then inspect the largest messages and check which ones include attachments.

Some classic Outlook versions also provide a Large Mail search folder under Search Folders. It groups messages above a chosen size threshold, but the feature and setup options can vary. Remember that a large message is not necessarily a message with a large attachment: lengthy email content or several smaller attachments can also increase its size.

To check file size itself, open the message and inspect the attachment details or save the file to a suitable location and view its properties. This is the reliable step when you need the size of a particular attachment rather than the overall email.

Why size results can be unexpected

Message size is not attachment size. The total includes the email and may include encoding overhead for attachments.
Several attachments add up. A message can cross a threshold even when no single file does.
Cloud links are different from attached files. A message containing a link to a cloud-stored file may be small; the linked file’s size may not be counted as an email attachment.
Search indexing may lag. New, moved, or imported messages might not appear immediately.
Scope and permissions limit results. Check the selected folder or mailbox and whether you can access the relevant shared mailbox.
Operator support varies. If larger: is treated as ordinary text, switch to filters, sorting, or a classic Outlook view.

Also check whether the search box is searching the current folder, the current mailbox, or multiple mailboxes. Searching a narrower location can make a valid query appear to fail.

Choosing the quickest method

For most users, begin with an attachment search and add a supported size operator. If that produces no useful results, choose based on what you need:

Find likely oversized emails quickly: search for messages with attachments and a size threshold.
Review a folder from largest to smallest: sort by Size in classic Outlook.
Confirm one file’s exact size: inspect or save that attachment and check its file properties.
Find a large cloud file: open the shared link and check the file in its storage location; Outlook’s message size is not the file’s size.

Searching by size is also useful for mailbox cleanup, but check the message and attachment before deleting anything. A large email may contain information you need, and removing a message may not remove a cloud-shared file or any copies stored elsewhere.

Frequently Asked Questions

What do I type in Outlook to find large attachments?
Try hasattachments:yes larger:5MB, changing the threshold as needed. Operator support varies, and the result refers to message size rather than necessarily the size of an individual file.

Can I search for attachments bigger than 10 MB?
Try hasattachments:yes larger:10MB if your Outlook search supports that syntax. Otherwise, filter for messages with attachments and sort by Size in classic Outlook, then verify the file itself.

Does Outlook show the attachment’s exact size?
Not through every message-size search. The search generally identifies emails by total message size. Open the message and inspect or save the attachment to confirm its individual file size.

Why does Outlook find no results for larger:5MB?
The operator may not be supported in your app, the selected search scope may be too narrow, or indexing may not be complete. Try the attachment filter, search a broader mailbox, or sort by Size in classic Outlook.

Can Outlook find files shared as links by size?
A link is not necessarily an attached file, so Outlook may only search the email containing it. Open the link and check the file’s size in the cloud storage location.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.