Outlook Search Not Working? Fixes for Classic, New Outlook and Mac

Outlook search failures come down to four things: the search is looking in the wrong place, Outlook doesn’t match words the way you expect, the mail you want isn’t downloaded to this computer, or the search index on your computer is broken. Only the last one needs a rebuild, and only in classic Outlook for Windows.

The quickest test is to run the same search in Outlook on the web. If the web finds the message and classic Outlook doesn’t, the problem is on your computer: the message is older than the mail Outlook keeps offline, or the local index or mailbox copy is damaged. If the web can’t find it either, the search terms are the issue, or the message isn’t in that mailbox at all.

Where each version of Outlook searches

Rebuilding the Windows index only helps classic Outlook for Windows, so check this table before re-indexing.

Even for Microsoft 365 mailboxes, a damaged index breaks classic Outlook search whenever it falls back to the PC, and it always breaks search of POP, IMAP and .pst mail.

Rule out scope and search terms first

Many “search is broken” reports, including an Outlook search no results screen, are search working as designed, so check these before touching the index.

Scope

In classic Outlook, the scope list next to the search box decides where Outlook looks: Current Folder, Subfolders, Current Mailbox or All Mailboxes. If you searched from inside one folder, you only searched that folder, so pick All Mailboxes and try again. To change the default, go to File > Options > Search.

Shared mailboxes and archives are the exception. Microsoft says All Mailboxes returns no results from a shared mailbox by design, so select a folder in it and search with Current Folder. Do the same with archive folders, one at a time.

How Outlook matches words

Microsoft documents a few rules that trip people up:

• Prefix matching. Searching ray finds ray, Ray, Raymond and rays, but not tray or disarray. Search from the start of a word.
• Short numbers are ignored. Strings of fewer than five digits return nothing, so a four-digit invoice or job number won’t be found. Search the customer name or subject instead.
• Numbers joined to words count as part of the word. Searching 365 won’t find Microsoft365.
• Punctuation is ignored, and only the first 1,000 results are returned. Narrow broad searches.

Use search keywords

Typing from:, subject:, hasattachment:yes or received:"this week" narrows results much faster than plain words. Keep the keyword and the value together with no space after the colon. Size keywords such as messagesize:large don’t work in the new Outlook.

Older or deleted emails missing from results

Outlook search not showing older emails, only recent ones? The index is probably fine: classic Outlook in Cached Exchange Mode keeps only a set period of mail on the PC, so a local search can’t see older messages; a rebuild won’t change that.

Classic Outlook

1. Go to File > Account Settings > Account Settings.
2. On the Email tab, select the account and click Change.
3. Drag the Download email for the past: slider right, or to All.
4. Click Next > Done and restart Outlook.

Expect a bigger .ost file and a long download, so avoid this on a PC short of disk space. For a one-off search, Microsoft says the Received date filter uses Microsoft Search to find mail outside the local sync window.

To include deleted mail, go to File > Options > Search, tick Include messages from the Deleted Items folder in each data file when searching in All Items and restart Outlook.

The new Outlook

For deleted mail, tick Include deleted items under Settings > General > Search and click Save. To keep more mail offline, choose a longer Days of email to save under Settings > General > Offline.

Classic Outlook: check and rebuild the index

1. Run the Indexer troubleshooter

In Windows 11, it’s under Settings > Privacy & security > Searching Windows; in Windows 10, run Search and Indexing from Settings > Update & Security > Troubleshoot.

2. Check Indexing Status

Click in the search box, then on the Search tab choose Search Tools > Indexing Status. Note the items remaining, wait five minutes and check again. If the number is falling, let it finish with the PC on and plugged in; if it never moves or shows 0 items indexed, the index is stuck.

3. Check Locations to Search

In the same menu, open Locations to Search and tick every mailbox and data file; an unticked .pst archive or account is never searched.

4. Make sure Outlook is being indexed

On the same Windows 11 page (just Search on some newer builds), choose Advanced indexing options or Customize search locations; in Windows 10, open Indexing Options from Control Panel. Click Modify and check that Microsoft Outlook is ticked.

5. Check the Windows Search service

Run services.msc and open Windows Search. Microsoft recommends a Startup type of Automatic (Delayed Start); start the service if it isn’t running. If Allow service to interact with desktop is ticked on the Log On tab, Outlook shows “No matches found” and the count never drops: exit Outlook, stop the service, clear the box, click Apply and start it again.

6. Rebuild the index

In Indexing Options, click Advanced (Windows may ask for administrator approval), then Rebuild. This recreates the search catalog without touching your email. Results stay incomplete until it finishes, which can take hours on a large mailbox, so leave Outlook open and the PC awake.

7. If one folder never shows results

For a Microsoft 365 or Exchange mailbox, the local copy of that folder may be damaged. After confirming its mail shows in Outlook on the web, use Clear Offline Items on the General tab of the folder’s Properties, then select the folder and press Shift+F9 to download it again. This isn’t for POP accounts or .pst files. If many folders are affected, rebuild the .ost as described in our guide to Outlook not opening; with an IMAP account, save the calendar and contacts first, since that file is their only copy.

8. If a rebuild didn’t help

Test a new mail profile, using the steps in that same guide. If search works there, the old profile is the problem; if not, Microsoft’s next steps are an Office Online Repair, then a reinstall.

If Windows search is broken everywhere, Microsoft’s “Fix problems in Windows Search” article has a reset script. It needs administrator rights and a temporary Unrestricted PowerShell execution policy, so leave it to whoever manages the PC.

Search errors: "Something went wrong" or "trouble fetching results"

With a Microsoft 365 or Exchange mailbox, classic Outlook asks the server first and falls back to your PC’s index if the server doesn’t answer in time. A failed server search can show messages like these:

• Something went wrong and your search couldn’t be completed.
• We’re having trouble fetching results from the server. Some items may not be included in your search results.

With the first, Microsoft says clicking Let’s look on your computer instead may show the expected results from the local index. If it’s a one-off, restart Outlook. Microsoft documents it failing every time in a second mailbox added to your profile as an extra Exchange account; see the admin workarounds below.

The new Outlook and Outlook on the web

The new Outlook for Windows searches Microsoft’s cloud copy of your mailbox, like Outlook on the web, so rebuilding the Windows index won’t fix it. If one finds a message and the other doesn’t, restart the new Outlook and update it.

Note two limits: it doesn’t search across accounts, so search All Folders in each account separately. And when there are many results, older items may not appear, so add a filter such as the sender or a date range.

Gmail and Yahoo accounts in the new Outlook can sync to the Microsoft Cloud for search, which keeps a copy of that mail, calendar and contacts in Microsoft’s data centers; check any company rules on where client email is stored first.

When the web can’t find a message either:

• Use fewer words: one distinctive word from the subject, or the sender with from: and a date with received:.
• Look in Deleted Items; a purged message won’t show in any search, though your admin may recover it.
• If it isn’t anywhere in the mailbox, including Junk Email, it may never have arrived. Our guide to Outlook not receiving emails shows how to find where it stopped.

Outlook for Mac

Microsoft 365 users, check this first: Microsoft says legacy Outlook for Mac stops working with Exchange Online (Microsoft 365) mailboxes starting October 2026, because the Exchange Web Services connection it uses is being retired. Turn off the Legacy Outlook toggle to switch to the new Outlook instead of repairing Spotlight.

Otherwise, legacy Outlook relies on macOS Spotlight indexing your profile. Check these in order:

1. Indexing isn’t finished. After a new profile, account or import, search shows little until Spotlight catches up.
2. The profile is excluded from Spotlight. Open System Settings > Spotlight > Search Privacy (on Ventura and Sonoma, Siri & Spotlight > Spotlight Privacy; on older versions, System Preferences > Spotlight > Privacy). Remove the entry for the profile you use (under ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles), or for a folder or drive containing it. Old profiles can stay excluded.
3. A slash (/) in the profile name. Microsoft says special characters break search; with Outlook closed, rename the profile’s folder without them.
4. A damaged Spotlight index. Microsoft’s “Troubleshoot search issues in Outlook for Mac” article covers checking for duplicate importers with mdimport -L and reindexing the profile with mdimport -g.

Microsoft’s last resort is reinstalling Office. If the new Outlook for Mac and the web both miss a message, recheck scope and search terms.

For admins: when search fails for several users

• Same build, same week. If several classic Outlook users lose search after an Office update, check Microsoft’s “Fixes or workarounds for recent issues in classic Outlook for Windows” page before rebuilding every PC’s index.
• Security baselines. Hardening scripts or Group Policy sometimes disable the Windows Search service or block Outlook indexing. If Microsoft Outlook is missing from Indexing Options on every PC, check policy first.
• Search errors in an added mailbox. Microsoft’s workarounds are policy values under HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\Search: ServerAssistedSearchTimeout (DWORD, in milliseconds; Microsoft suggests testing 5000) makes Outlook wait longer for the server; DisableServerAssistedSearch set to 1 turns server search off, leaving only downloaded mail searchable. Back up the registry first, since a wrong edit can cause serious problems.
• Finding a specific message. Message trace in the Exchange admin center confirms whether it arrived. Content search in Microsoft Purview reaches other people’s mailboxes, so it needs eDiscovery permissions and should follow your company’s email policy; for a legal dispute, talk to your attorney first.

Microsoft 365 administration, such as user changes, password resets and security setup, is part of our Microsoft 365 management and the Business Support Plan, which also includes unlimited remote help desk tickets for problems like this.

When it’s the computer, not Outlook

Indexing reads every message on disk, so on a PC with a slow or failing drive or little free space it may never finish, however often you rebuild. If the disk is constantly at 100% in Task Manager, see 100% disk usage in Windows 11 first. A .pst archive of tens of gigabytes also slows indexing; splitting old mail into another archive helps.

A failing drive has to be replaced in person, so back up anything stored only on that PC, including .pst files, before it gets worse. If the drive is healthy and you’d rather not dig through services and indexing settings yourself, this is a typical $59 remote fix.

Common questions

Why is Outlook search not showing recent emails?

In classic Outlook, mail in POP or IMAP accounts and .pst files shows up in search only after Windows indexes it, and Microsoft 365 mailboxes fall back to that same index when the server search fails or you’re offline. If indexing is stuck, recent mail can be missing while older mail still shows. Check Search Tools > Indexing Status. If the count of items remaining never drops, check that the Windows Search service is running and rebuild the index from Indexing Options > Advanced.

How long does it take to rebuild the Outlook search index?

It depends on the size of your mailbox and the speed of the drive. A small mailbox can finish within an hour, while a large mailbox or big .pst archives can take several hours or overnight. Leave Outlook open and the computer awake and plugged in. Search results stay incomplete until it finishes.

Does rebuilding the search index delete any email?

No. Rebuilding deletes and recreates the Windows search catalog, which is only a list of words pointing to your messages. Your mailbox, .ost and .pst files aren’t changed. The only side effect is that search in Outlook and File Explorer is incomplete while the new index builds.

Why does Outlook find nothing when I search for an invoice number?

Microsoft says Outlook ignores number strings shorter than five digits, so a four-digit invoice or job number returns no results even when it appears in the email. Numbers attached to words are also treated as part of the word. Search for the customer name, the sender with from:, or a word from the subject instead.

Why does search work in Outlook on the web but not in the desktop app?

Outlook on the web searches the mailbox on Microsoft’s servers. Classic Outlook also asks the server first for Microsoft 365 mailboxes, but falls back to the Windows index on your PC when offline or when the server search fails, and uses that index for POP, IMAP and .pst mail. So a desktop-only miss points to the PC: mail older than the offline sync period, a damaged or incomplete index, or an out-of-sync local copy.

Why can’t Outlook search find older emails?

In classic Outlook, Cached Exchange Mode keeps only a set period of recent mail on the PC, so searches of the local copy can’t see anything older. Go to File > Account Settings > Account Settings, select the account, click Change and drag the Download email for the past slider further right, or to All, then restart Outlook. Expect a larger .ost file and a long first sync. In the new Outlook, the matching setting is Days of email to save under Settings > General > Offline.

What does ‘Something went wrong and your search couldn’t be completed’ mean in Outlook?

It appears when classic Outlook’s server search for a Microsoft 365 or Exchange mailbox fails. Microsoft says choosing Let’s look on your computer instead may show the results you expected, because it searches the mail stored on your PC. If it happens every time, especially in a second mailbox added to your profile, an admin can make Outlook wait longer for the server or turn server search off by policy.