Outlook Search Not Finding Emails That Exist? Fixes for Every Version

Outlook search usually misses an email that exists for one of four reasons: the search covers only the current folder, the email is older than the part of the mailbox Outlook keeps on your computer, the search index hasn't finished, or the word you typed sits in the middle of a longer word. The fastest fix is to switch the search scope to All Mailboxes (classic Outlook) or All folders (new Outlook and Outlook on the web) and search again. If the email still doesn't appear, the causes and fixes differ by version, so jump to yours below.

Jump to: Classic Outlook for Windows · New Outlook for Windows · Outlook on the web · Outlook for Mac · FAQ

Why Outlook search misses emails that are right there

There isn't one cause — there are several, and they stack on top of each other.

The search scope is too narrow. Outlook can search just the folder you have open. Search from the Inbox and an email you filed in another folder, or one in Sent Items, won't appear.

The email isn't on your computer. Classic Outlook with a Microsoft 365 or Exchange account normally runs in Cached Exchange Mode and keeps only part of the mailbox offline. Microsoft's default is 1, 3 or 12 months, depending on the size of your disk. Older mail stays on the server, and search shows it only when you ask for more.

The local index is incomplete. Classic Outlook searches through Windows Search. After a new profile, an Office repair or a large import, items still waiting to be indexed are missing from results, and Outlook doesn't warn you: you have to check the indexing status yourself.

Results are capped. Microsoft says Outlook returns only the first 1,000 search results, and that new Outlook may not display older items when a search finds too many. A broad search for a common name can push the email you want out of the list.

Prefix-only matching. Outlook matches from the start of a word. Search "discretion" and you'll find "discretionary," but search "cretionary" and you'll find nothing. If you only remember a fragment from the middle of a word, Outlook can't help you.

Numbers under five digits are ignored. This one surprises everyone: Microsoft documents that strings of numbers shorter than five digits are skipped. Searching "9810" will not find "98101."

Classic Outlook for Windows

This is Outlook for Microsoft 365, 2024, 2021, 2019, 2016 and 2013: the version with a File menu and a ribbon. Try the steps in order; the first two are the quickest.

1. Set the search scope to All Mailboxes

Click in the search box and look at the scope menu next to it. Current Folder searches only the folder you have open; All Mailboxes searches every folder of your mailboxes. Deleted Items are left out unless you turn on the option to include them under File → Options → Search. One exception: Microsoft notes that All Mailboxes returns limited or no results from an Online Archive, so for archived mail select the archive folder and search Current Folder.

2. Click More, or keep the whole mailbox offline

If the results end with Showing recent results... More, Outlook has searched only the mail stored on your PC. Clicking More fetches older matches from the server. That is Cached Exchange Mode at work: Microsoft's default keeps 1, 3 or 12 months of mail offline, depending on the size of your disk. Searching while offline ends with Server unavailable and the number of months that were searched.

To keep the whole mailbox on your PC, go to File → Account Settings → Account Settings, select your Exchange or Microsoft 365 account and click Change, move the Download email for the past slider to All, then click Next and restart Outlook. Outlook then downloads and indexes the older mail, which takes a while on a large mailbox.

3. Turn off the results limit

Classic Outlook has an option that trades completeness for speed. Under File → Options → Search, clear Improve search speed by limiting the number of results shown, then search again.

4. Check indexing, then rebuild the index

If recent emails are the ones missing, or search finds nothing at all, check the index. Click in the search box, then choose Search Tools → Indexing Status. If items remain to be indexed, note the number and check again after five minutes. If it isn't going down, Microsoft's checklist is: every data file ticked under Locations to Search in the same Search Tools menu, the Windows Search service running (startup type Automatic (Delayed Start) in services.msc), and Microsoft Outlook listed under Included Locations in Indexing Options.

Then rebuild: close Outlook, open Control Panel → Indexing Options → Advanced and click Rebuild. Searches made before indexing finishes return partial results. Our guide to Outlook indexing that is slow or stuck covers how to tell when it is done and what to do when it stalls.

5. Disable server-assisted search (DisableServerAssistedSearch)

With a Microsoft 365 or Exchange account, classic Outlook can send searches to the search service in Exchange instead of searching your PC. Microsoft documents a registry value that turns this off and makes Outlook use the local Windows Desktop Search index. It lists it as a workaround when search results misbehave beyond the sync window, and when searching an additional mailbox fails with Something went wrong and your search couldn't be completed.

Note: Editing the registry carries risk. Back up first, and only do this if you're comfortable with it.

Microsoft gives this Group Policy location:

HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\Search
DisableServerAssistedSearch = 1 (REG_DWORD)

Its articles name HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Search as the equivalent location outside Group Policy. Restart Outlook afterwards. The trade-off: local search only sees mail stored on your PC, so pair this with the slider at All (step 2), or older email drops out of the results. Delete the value to undo it.

New Outlook for Windows

None of the classic steps above apply to new Outlook: there are no indexing options or registry values to change. Microsoft's troubleshooting for new Outlook goes through its own settings.

• Scope. Go to Settings → General → Search and check which folders search covers by default. If it is set to Current folder, emails outside the open folder won't appear; search All folders instead.
• Too many results. Microsoft says that if new Outlook finds too many results, older items may not be displayed. Narrow the search with filters (sender, date range, attachments) rather than scrolling.
• Several accounts. Microsoft says multi-account search is not currently supported. Select each account in turn and search All folders.
• Deleted items. Turn on Include deleted items under Settings → General → Search and select Save.
• Older mail offline. Under Settings → General → Offline, choose a longer period in Days of email to save and select Save.
• Online Archive. New Outlook searches it automatically and includes the results, so an archived email that classic Outlook misses can show up here.

For where the search box, filters and scope sit in each version of Outlook, see how to search in the Outlook app.

Outlook on the web

Outlook on the web searches the mailbox held in Microsoft 365, so nothing stored on your PC is involved. That makes it a useful test: if an email appears there but not in classic Outlook, the cause is on your PC (scope, sync window or index), not in the mailbox.

When it misses something in the browser too, use Filters at the end of the search box: Folders, From, To, Subject, keywords, date ranges and attachments. Only the first 1,000 results are returned, so a date range or a sender usually brings an older email into view faster than a broader search. To leave search, choose any folder in the navigation pane.

Outlook for Mac

Outlook for Mac comes in two versions that search in different ways.

New Outlook for Mac: Microsoft says its search is powered by Microsoft Search, so the Spotlight steps below are for legacy Outlook. If new Outlook misses an email, try the same search in Outlook on the web and narrow it with filters.

Legacy Outlook for Mac relies on Spotlight, the macOS index. Microsoft's steps: after a new profile, a new account or an import from a PST or OLM file, wait for indexing to finish; make sure your Outlook profile folder, or a folder above it, is not in Spotlight's Privacy list; then check for duplicate Outlook importers with mdimport -L and reindex the profile. Microsoft also says support for legacy Outlook for Mac ends in October 2026.

Skip the old OutlookSearchRepair tool: Microsoft's download is gone, and the tool does not work on macOS 10.14 or later. Our Outlook for Mac search guide has the full reindex commands.

On every version: how you type the search

Because of prefix matching, search the beginning of the word you remember rather than the middle. Numbers joined to a word count as part of it, so "365" won't find "Microsoft365"; for a short number, search a longer neighbouring word instead. To go straight to a sender, a date or an attachment, use operators such as from: and received:, listed in our Outlook search operators cheat sheet.

When the email is missing everywhere

If the email doesn't appear even in Outlook on the web with the right folder and date range, check Deleted Items and, on a work account, the Online Archive. If search fails outright, with errors or no results for anything, see Outlook search not working. And if the web finds the email but your desktop Outlook keeps missing it after these steps, the gap is in the local search.

A different way to search your inbox

Inbox Search is an Outlook add-in that builds its own search index of your mailbox on your device, so what it finds doesn't depend on Outlook's scope menu, offline sync window or result cap. It indexes your primary mailbox, all folders included; it doesn't cover the Online Archive or shared mailboxes.

It also matches by meaning, not just exact words, so "the invoice from the Berlin trip" finds the right message even if those exact words aren't in it. The index stays on your device and email content is not sent to our servers. It works in Outlook on Windows, Mac and the web; keyword search is free and unlimited, and AI search is free for 5 finds a day.

Still stuck? For a detailed look at how Inbox Search compares to other tools, see our comparison of the best Outlook search tools.