Autocomplete for email addresses no longer working

Question

When sending an email, I could previously type the first letter of an email address and would receive several options for complete email addresses. Suddenly as of yesterday, this has stopped and no longer do email addresses automatically populate. I have to type the complete email address. How can this be resolved?

Answer 1

In Outlook, the AutoComplete list that suggests email addresses can stop working if the feature is turned off or the cache becomes corrupted. Use these steps to restore it (steps are shown for Outlook desktop, but the same underlying AutoComplete behavior applies):

1. Confirm AutoComplete is enabled
   1. In Outlook, select File > Options.
   2. Select the Mail tab.
   3. Scroll to the Send messages section.
   4. Make sure Use Auto-Complete List to suggest names when typing in the To, Cc, and Bcc lines is checked. If it was unchecked, check it and then send a few test messages to rebuild the list.
2. Clear and rebuild the AutoComplete list (if it is enabled but not working)
   1. In the same Mail options page, under Send messages, select Empty AutoComplete List.
   2. Confirm by selecting Yes.
   3. Send a few test emails to the same addresses to repopulate the AutoComplete list.
3. Reset the AutoComplete cache if it is corrupted If AutoComplete is enabled and still not working after clearing the list, the cache may be damaged and must be reset. For a home/non‑Exchange account:
   1. Close Outlook.
   2. Select Start, then type or paste: %LOCALAPPDATA%\Microsoft\Outlook and open that folder.
   3. Right‑click the RoamCache folder, select Rename, and rename it to old_RoamCache.
   4. Start Outlook again; a new RoamCache folder will be created automatically.
   5. Send a few emails to rebuild AutoComplete.
   For an Exchange account:
   1. In Outlook, go to File > Info > Account Settings and confirm the account type is Microsoft Exchange.
   2. Turn off Cached Exchange Mode:
      • File > Account Settings > Account Settings.
      • Select the Exchange account > Change.
      • Clear Use Cached Exchange Mode, select Next, then Finish, and close the dialog.
   3. Close Outlook.
   4. Go to %LOCALAPPDATA%\Microsoft\Outlook and rename RoamCache to old_RoamCache.
   5. Restart Outlook; a new RoamCache folder will be created.
   6. Turn Cached Exchange Mode back on using the same Account Settings path and re‑enable Use Cached Exchange Mode.
4. Check for interfering add‑ins (if the issue started suddenly) Some add‑ins, such as older versions of the iTunes Outlook Change Notifier add‑in, can interfere with AutoComplete.
   1. In Outlook, select File > Options > Add‑Ins.
   2. At the bottom, next to Manage COM Add‑ins, select Go….
   3. Find Outlook Change Notifier (if present) and clear its checkbox.
   4. Select OK, then restart Outlook and test AutoComplete again.

If these steps are followed, AutoComplete suggestions should start appearing again as new messages are sent and the list is rebuilt.

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References:

• AutoComplete not working correctly in Outlook 2010
• Outlook does not add recipients to the Auto-Complete cache
• Internal recipient's address isn't autocompleted or suggested
• Outlook replies or forwards cause non-delivery error “Your message did not reach some or all of the intended recipients”

Answer 2

Hi DZ

Thank you for reaching out to the Microsoft Q&A forum. I understand recipient AutoComplete/suggestions in Outlook on the web stopped appearing when you type in the To/Cc/Bcc fields, so you now have to type the full address. 

First, please confirm whether you’re using Outlook.com (personal) (for example, outlook.live.com) or Outlook on the web for a work/school mailbox (outlook.office.com), and which browser you’re using.  

Meanwhile, if your account is personal, please try these workarounds (web-specific): 

• If suggestions don’t appear while typing, use the To/Cc/Bcc button to open the recipient picker and search your contacts/address list directly. 
• Test in a private/incognito browser window and, if possible, a different network to rule out browser/session or network-related behavior affecting suggestions in Outlook on the web.  
• In Outlook on the web, check the Suggested people setting under Settings > General > Privacy and data (or search “Suggested people” in Settings). If it’s disabled or the data is stuck, use the Clear data option there to reset the expanded suggestions behavior.  

Please tell me how it goes. If the problem persists, please don’t hesitate to reply to this thread and I will be happy to help. Have a lovely day!   

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