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How to Fix Outlook AutoComplete Not Working or Suggesting Wrong Emails

Applies toMicrosoft 365Outlook
3 min fix Updated 20 Jul 2026

By , 10+ years in IT support and helpdesk How these guides are checked

Quick Answer

Start a new email, begin typing the incorrect name, and when the suggestion pops up, click the small X next to the name to delete it from the cache.

Checked against Microsoft Learn - new Outlook for Windows, Microsoft 365 Roadmap and between 5 Aug 2026 and 12 Sep 2026. Nothing published in that period has been linked to this guide.

Estimated Time to Fix: 3 minutes

Summary ​

This article guides you through fixing Outlook's AutoComplete list when it fails to suggest email addresses or suggests incorrect ones.

Symptoms ​

  • When you start typing an email address in the To, Cc, or Bcc fields, Outlook doesn't suggest any names.
  • Outlook suggests outdated or incorrect email addresses for people you email frequently.

Before You Start ​

  • None required.

Instructions ​

1. Remove an Incorrect Suggestion ​

Deleting one wrong entry is the fix when Outlook keeps offering an old or misspelled address.

  1. Open Outlook and start a New Email.
  2. Begin typing the name or email address of the person in the To field.
  3. When the incorrect suggestion appears in the dropdown list, hover your mouse over it.
  4. Click the X icon next to the suggestion to remove it.
  5. Type the correct email address manually and send the email. Outlook will remember the correct one next time.

If no dropdown appears at all when you type a name, there is no suggestion to delete and the feature itself is switched off — go to Step 2. If the wrong address reappears after you remove it, the cached list needs wiping — go to Step 3.

2. Enable the AutoComplete Feature ​

If no suggestions appear at all, the feature itself has been switched off.

  1. Open Outlook and click on File in the top left corner.
  2. Click Options at the bottom left.
  3. Select Mail from the left menu.
  4. Scroll down to the Send messages section.
  5. Check the box for Use Auto-Complete List to suggest names when typing in the To, Cc, and Bcc lines.
  6. Click OK to save your changes.

3. Clear the Entire AutoComplete List ​

Wiping the list resets a cache that has stopped updating or filled up with stale addresses.

  1. Open Outlook and navigate to File > Options > Mail.
  2. Scroll down to the Send messages section.
  3. Click the Empty Auto-Complete List button.
  4. Click Yes to confirm. (Note: This will erase all saved suggestions. Outlook will rebuild the list as you send new emails).

4. Verify Success ​

Start a new email and type a familiar name to confirm suggestions behave the way you expect.

  1. Start a new email and type a recipient's name. The correct suggestion should appear (or no suggestion if you cleared the list).

Troubleshooting ​

WARNING

If you use Outlook on the Web or the "New" Outlook, the AutoComplete list syncs with your Microsoft 365 account. If clearing it doesn't work, try signing out and signing back in.

Symptom / ErrorPotential CauseSolution
List empties every time you restart OutlookCorrupt Outlook profile or data fileHow to Submit an Effective IT Support Ticket
AutoComplete setting is greyed outOrganization policyYour company may have disabled this feature.

Last updated:

Frequently asked questions

Does AutoComplete use my Contacts list?
No. AutoComplete is completely separate from your address book. It is a hidden cache of the last 1,000 email addresses you have recently sent messages to.
How do I completely wipe my AutoComplete list and start over?
Go to File > Options > Mail, scroll down to the Send messages section, and click the 'Empty Auto-Complete List' button.