autofill contacts not detected

In the new Outlook, contact auto-complete relies on the contact data that is actually available and synced in that client. If names are not being detected when typing in To/Cc/Bcc, the usual causes are:

1. AutoComplete cache is empty or reset
   • AutoComplete suggests names based on recipients used previously in that client. If the cache is new or was cleared, names will not appear until messages are sent to those recipients again.
   • After sending to a recipient, Outlook adds it to the AutoComplete cache so it can be suggested next time.
2. AutoComplete cache is corrupted
   • When the cache is corrupted, Outlook may fail to add or suggest recipients.
   • The supported fix is to clear the AutoComplete cache so Outlook can rebuild it:
     • In Outlook, go to File → Options → Mail.
     • Under Send messages, ensure “Use Auto-Complete List to suggest names when typing in the To, Cc, and Bcc lines” is checked.
     • Use the option to clear or empty the AutoComplete list (this removes all stored entries), then restart Outlook and send new messages so the cache repopulates.
3. Contact groups or specific contact types
   • Certain builds of Outlook have known issues where local contact groups do not auto-resolve via Autocomplete. In those cases, typing the full name and using a resolve shortcut (Alt+K or Ctrl+K) is required as a workaround.

If contacts are visible in People but still not suggested, focus on:

• Verifying AutoComplete is enabled.
• Clearing the AutoComplete cache and letting it rebuild by sending new messages.
• For contact groups, typing the group name and pressing Alt+K/Ctrl+K to resolve.

References:

• AutoComplete not working correctly in Outlook 2010
• Outlook does not add recipients to the Auto-Complete cache
• Contact Groups are not searchable with Autocomplete