Clear Outlook Roam Cache: Safe Steps and What Changes

To clear Outlook’s Auto-Complete suggestions, open classic Outlook for Windows and select File > Options > Mail > Empty Auto-Complete List, then confirm. If you specifically need to reset the local RoamCache files, close Outlook and rename only the Stream_Autocomplete*.dat file in your Outlook RoamCache folder; don’t delete the whole folder. The built-in command is the safer first choice because “RoamCache” can contain more than recipient suggestions.

What Outlook’s RoamCache means

RoamCache is a folder used by classic Outlook for Windows to keep certain local data. One type of file you may find there is named Stream_Autocomplete followed by additional characters and the .dat extension. It is associated with Outlook’s Auto-Complete feature, which displays suggested email addresses or names as you type in the To, Cc, or Bcc field. That suggestion list is different from your contacts and from the address book directory you can search.

People often search for “clear roam cache Outlook” because a recipient suggestion is wrong, missing, duplicated, or no longer wanted. In that situation, the problem may be the Auto-Complete list, but not every item in RoamCache is an Auto-Complete file. Nor does clearing a local file necessarily erase every source Outlook can use to suggest recipients. Your Outlook version, account type, and organization’s Microsoft 365 or Exchange configuration can affect where suggestions are stored and how they return.

The folder is typically at %LOCALAPPDATA%\Microsoft\Outlook\RoamCache in Windows. The environment-variable path is useful because the Windows user name and profile folder differ from computer to computer. It refers to classic Outlook’s local data location; it is not a universal location for every Outlook app or platform.

Use Outlook’s built-in clear command first

If your aim is simply to remove the remembered recipient suggestions, use Outlook’s own control before touching files. In classic Outlook for Microsoft 365 on Windows:

Open Outlook and select File.
Select Options, then Mail.
Under the message-related options, select Empty Auto-Complete List.
Confirm that you want to clear the list.

This removes the Auto-Complete suggestions Outlook has accumulated, rather than deleting contacts from your Contacts folder. It does not remove messages, alter your mailbox folders, or delete entries from your organization’s address book. After clearing it, Outlook may build suggestions again as you send messages, so a name can reappear after you use that address.

Use this option when you want a general reset, such as clearing many old suggestions before handing a computer to another person. If you only need to remove one incorrect suggestion, you may be able to highlight it in the suggestion list and choose the displayed remove control, often an X. The exact interaction can vary by Outlook build and whether you are composing in classic Outlook or another Outlook app.

Reset the local Auto-Complete cache manually

Manual file work is most relevant when classic Outlook’s suggestions remain broken after using the built-in control, or when support guidance specifically asks you to refresh the local cache. First close Outlook normally. Check that it has finished closing before changing files; if Outlook is still running, it could recreate or keep a file open. Avoid ending unrelated Office or Windows processes just to force a reset.

Press Windows key + R to open the Run dialog.
Enter %LOCALAPPDATA%\Microsoft\Outlook\RoamCache and press Enter. You can also paste the path into File Explorer’s address bar.
Look for a file whose name begins Stream_Autocomplete and ends in .dat. If extensions are hidden, use File Explorer’s view options to show file name extensions before identifying files.
For a reversible change, rename the relevant file, for example by adding .old to its name. Do not rename or remove unrelated files.
Open Outlook again and check whether the issue has changed. Outlook may create a fresh local cache as needed.

Renaming is safer than permanent deletion because you can restore the original file if the reset causes an unexpected result. If there are several similarly named files, don’t guess which one is active or remove every file in the directory. Keep Outlook closed, make a backup copy, and ask your organization’s IT support to identify the correct file if the distinction is unclear. Manual cache handling should be a targeted troubleshooting step, not routine maintenance.

What clearing it changes—and what it does not

Clearing the Auto-Complete list means Outlook may stop offering previously used recipient suggestions. It does not erase the underlying email addresses from messages you have already sent, remove people from your Contacts folder, or prevent you from typing an address manually. You can still use the address book or directory search to find a person, provided that person is present in the relevant contacts or directory.

A suggestion is not proof that an address is current or valid. Auto-Complete can remember an address that has since changed, and selecting it may send a message to an old mailbox. Conversely, deleting a suggestion does not block that address or prevent it from receiving mail if you enter it again. If the concern is a mistaken or sensitive recipient, review the recipient field carefully before sending and remove the suggestion using the available Outlook control.

Clearing the local file also is not the same as clearing every account-level or organization-level source of recipient information. In some setups, suggestions can be associated with the mailbox or account and may return after Outlook reconnects or synchronizes. Thus, if an address comes back, it does not automatically mean the file reset failed; another source may be providing it.

Classic Outlook, new Outlook, and other platforms

The RoamCache file method applies to classic Outlook for Windows. The new Outlook for Windows is a different app experience and should not be assumed to use the same local folder or file-reset procedure. Outlook on the web, Outlook for Mac, and mobile Outlook also do not use the Windows RoamCache path as a general cache-clearing instruction. Don’t follow a classic Outlook file procedure on those versions unless current guidance for that specific app tells you to.

To identify which Windows app you are using, check the app’s title or its Outlook settings and menu layout. Classic Outlook has the traditional desktop File tab and the File > Options settings path described above. If you are in new Outlook and cannot find that path, use the controls available in that app or consult your organization’s support team rather than deleting files from a different Outlook installation. The same caution applies on a shared or managed computer: your administrator may control app versions and account settings.

On a Mac, Windows keyboard shortcuts and Windows folder paths do not apply. Outlook for Mac has its own account and data-management behavior, so use its current in-app settings or Microsoft support instructions for the installed version. Avoid trying to locate or remove a Windows RoamCache directory on a Mac.

When clearing the cache may help

A reset is reasonable when the symptom is specifically about remembered recipient suggestions. Examples include Outlook repeatedly offering an obsolete address, a suggestion appearing with a misspelled display name, or a local Auto-Complete list behaving inconsistently after a profile or account change. First test the built-in clear command, especially if the issue is limited to unwanted suggestions.

It is less likely to help with problems such as a mailbox that will not synchronize, messages stuck in the Outbox, a corrupt Outlook profile, or an unavailable address book. Those symptoms have other possible causes, including connectivity, account configuration, service availability, or profile issues. Deleting cache files at random can make troubleshooting harder without fixing the underlying fault. Note the exact symptom and any error message before changing files, so you can report useful details to support.

If a single suggestion returns, check whether you used that recipient again, whether another device is using the same account, and whether the suggestion appears in Outlook on the web as well. These observations help distinguish a local Windows cache issue from a suggestion supplied elsewhere. They are clues, not a guaranteed diagnostic test, because account behavior differs.

Safety and practical precautions

RoamCache is not a folder to clean out casually. Some files can support Outlook features beyond the one you are troubleshooting, and the contents can vary. Back up or rename a targeted file rather than deleting the entire directory. Never remove your Outlook data file, mailbox, or profile as a substitute for clearing Auto-Complete; those are different components and can affect access to mail or settings.

Close classic Outlook before renaming cache files.
Use the built-in Auto-Complete command for a general recipient-suggestion reset.
Target only a clearly identified Stream_Autocomplete file when manual steps are warranted.
Keep a reversible backup until Outlook has reopened and you have checked the result.
On a work-managed device, ask IT before changing application data if policy or account behavior is uncertain.

These steps do not require third-party “Outlook cleaner” utilities. Be cautious with tools that promise to clear every Outlook cache at once: broad cleanup can affect data unrelated to Auto-Complete, and it may not remove suggestions stored or supplied by an account. A narrowly defined symptom calls for a narrowly defined reset.

Frequently Asked Questions

Does clearing Outlook RoamCache delete my contacts?
No. Clearing the Auto-Complete list removes remembered recipient suggestions, not entries in your Contacts folder. Contacts and Auto-Complete are separate features, though both can help you address a message.

Will the suggestions come back after I clear them?
They can. Outlook may create suggestions again as you send mail, and account or organization settings may provide suggestions from another source. If an unwanted entry returns without you using it, compare behavior across devices or ask your administrator about the account configuration.

Should I delete the whole RoamCache folder?
No. Start with Outlook’s built-in Empty Auto-Complete List command. If a manual reset is necessary, close classic Outlook and make a backup or rename only the clearly identified Auto-Complete file; leave other files alone.

Is RoamCache the same as the Outlook OST file?
No. RoamCache contains local cache data such as Auto-Complete-related files, while an OST is a separate Outlook data file used with certain account configurations. Removing or rebuilding an OST is not the same fix and should not be done just to clear recipient suggestions.

Why can’t I find File > Options in Outlook?
You may be using new Outlook, Outlook on the web, or another platform rather than classic Outlook for Windows. The menu path and local files differ. Use the controls for your specific app, and don’t apply the Windows RoamCache instructions to Mac or web Outlook.

Will clearing the list stop Outlook from suggesting a person forever?
Not necessarily. The cleared suggestion can be learned again when you send to that address, and other directory or account-based suggestions may still be available. Clearing Auto-Complete is a reset of remembered suggestions, not a block or permanent suppression rule.

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