Auto-complete contact in field 'to' stopped working - Outlook

Question

Auto-complete contact in field 'to' stopped working - Outlook

Olivier CARAVERA 0

Hello,

In my organistion, just one person have this problem, how can i solve that ?

Is there a PowerShell command to clear the cache or to enable/disable the option to force it?

Best regards

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3 answers

Your answer

Answer 1

Aetherin 2,505 Independent Advisor

Hi @Olivier CARAVERA,

Since this occurs in Outlook on the web and affects only one user, I would first recommend testing in an InPrivate/Incognito window or a different supported browser. If AutoComplete works there, clear the cookies and site data for Outlook in the user's regular browser and then sign in again.

There is no documented Exchange Online PowerShell command to enable, disable, or clear the Outlook on the web AutoComplete list. The cache-clearing switches available for Outlook desktop do not apply to Outlook on the web.

If the issue persists, could you please provide a few additional details?

Does AutoComplete fail for all recipients, or only for certain recipients (for example, specific internal users)?
When composing a message, can the affected user still locate the recipients through the organization's address book?
Does the same behavior occur when using the Outlook desktop application, or is it limited to Outlook on the web?

Please kindly review the information above and give it a try. If there are any updates, please feel free to reply to me. I look forward to hearing back from you and will be happy to assist further if needed.

Thank you so much for taking the time.

Olivier CARAVERA 0 Reputation points

2026-10-02T15:02:03.66+00:00

AutoComplete on all computer but only with an account. The account is only for outllook web.
Aetherin 2,505 Reputation points Independent Advisor

2026-10-04T14:47:31.5566667+00:00

Hi @Olivier CARAVERA,

Thank you for your reply.

If you are an end user, please contact your Microsoft 365 administrator and ask them to open a support ticket with Microsoft for the affected user. A Microsoft support engineer can perform a remote session, review the relevant backend configurations, and run any necessary synchronization or diagnostic tools.

Since the issue affects only one account across multiple computers, further backend investigation may be required.

Answer 2

Olivier CARAVERA 0

on https://outlook.cloud.microsoft

0 comments

Answer 3

For a single affected user, start with the supported user-side fixes:

Verify AutoComplete is enabled in Outlook:
- File > Options > Mail
- Under Send Messages, confirm Use Auto-Complete List to suggest names when typing in the To, Cc, and Bcc lines is selected.
Clear the user’s AutoComplete list:
- File > Options > Mail
- Under Send Messages, select Empty Auto-Complete List
- Confirm with Yes
Alternatively, start Outlook with the cache reset switch:
- Outlook.exe /CleanAutoCompleteCache
If the issue is only for certain internal recipients in Outlook on the web or Outlook, check whether the user has an address book policy (ABP) applied. If GAL segmentation is in use and the recipient is not included in the address lists available to that user, the address will not be autocompleted or suggested.
- Workarounds supported in that case:
  - Add the recipient as a personal contact in Outlook or OWA
  - Remove the address book policy if it is no longer needed

About PowerShell: no supported PowerShell command is provided here to clear the AutoComplete cache or toggle the AutoComplete option for the user.