How to Fix Outlook AutoComplete Not Working Issue in 2025?

OST to PST Converter /July 30, 2025

Outlook is popular for its easy-to-use features and is a top choice for both personal and work emails. One helpful tool is AutoComplete, which suggests email addresses in the “To” field based on past emails. But when this feature stops working, it can be frustrating and slow things down. In this blog, you will know why AutoComplete might not work in Outlook and get simple steps to fix the problem right below.

What Refers to the “Outlook AutoComplete Not Working” Issue?

The “AutoComplete Not Working” issue in Outlook occurs when it does not suggest email addresses you have used before when writing a message. Normally, when you start typing in the ‘To,’ ‘Bcc,’ or ‘Cc’ fields, Outlook shows a list of familiar contacts. If this feature stops working, you have to find or type full email addresses yourself, which takes more time and effort.

AutoComplete Not Working in Outlook: Why?

  • AutoComplete is turned off in settings
  • The cache memory is full
  • The AutoComplete cache is damaged
  • The user profile has errors
  • Outlook is not updated to the latest version
  • The RoamCache folder is corrupted
  • The OST file is too big or broken
  • The mailbox is too large
  • Some third-party add-ins are causing issues
  • Outlook files are damaged or missing

Steps to Fix the “Outlook AutoFill / AutoComplete Not Working” Issue
Method 1: Enabling the AutoComplete Option in Outlook

Sometimes, users do not realize that Outlook’s AutoComplete feature is turned off because of default settings or accidental changes. When it is off, Outlook will not show suggested email addresses when you type. To fix this, check if the feature is turned on by following these simple steps:

  • Open Microsoft Outlook and click on the File menu.
  • Now, click on Options and then go to the Mail tab.
  • Scroll down to the Send Messages section.
  • Make sure that the box for ‘Use Auto-Complete List to suggest names when typing in the To, Bcc, and Cc lines’ is checked.
  • After that, tap on Empty Auto-Complete List and then click Yes to confirm.
  • Lastly, click OK to save the changes.
  • Now, try sending a new email to check if AutoComplete is working again.

Methods 2: Using Goldytools OST to PST Converter

The Goldytools OST to PST Converter is a helpful tool that lets you turn unreadable OST files into Outlook PST files. It safely extracts all mailbox items and converts them without losing any data. You can also save the files in other formats like MSG and EML.

  • Lets you convert the first 20 emails from each folder for free
  • Allows you to convert many OST files to PST at once
  • Converts all email items like emails, calendars, contacts, tasks, journals and notes
  • Supports OST files from IMAP, Office 365, Exchange, Hotmail, and Outlook.com
  • Works without needing an Exchange profile or server connection
  • Repairs and converts damaged OST files to formats like PST, MSG, EML, HTML, MHT and PDF
  • Allows you to split or compress large PST files easily
  • Allows searching OST data by field names like subject or date
  • Supports all Outlook versions from 2000 to 2019
  • Converts OST files from Hosted Exchange and Online Exchange
  • Converts large and password-protected OST files to PST format

Conclusion

Outlook’s AutoComplete helps you send emails faster, but sometimes it stops working due to things like cache problems or outdated software. If the issue is with a damaged OST file, a tool like OST to PST Converter like given above can be a perfect solution.

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