Outlook builds its AutoComplete list from the people you email. Microsoft describes no direct restore feature. Send a message to a contact and Outlook adds the entry again. Older nickname files can be imported. Another Microsoft article explains how to copy the list to another computer.
You cleared the list or removed a name and now Outlook stops suggesting it. Your fix depends on how the entry disappeared.
Facts follow Microsoft Learn on the Outlook AutoComplete list.
What is the AutoComplete List in Outlook?
Microsoft also calls the list the nickname cache. Outlook creates it when you send mail and stores SMTP addresses, display names and Exchange entries for the people you email. Microsoft states the list stores up to 1,000 entries in Outlook for Microsoft 365, 2019 and 2016.
How to Restore a Removed Entry?
Microsoft states that emailing the contact again restores their information to the list. Removing a single entry does not delete the contact from your account.
- Open a new message.
- Send it to the contact you want back.
- Type the first characters of the name in the To line and check the suggestion.
Can You Restore an Older NK2 File?
Outlook 2007 and earlier stored the list in a nickname (.nk2) file. Outlook 2010 and later store it as a hidden message in your primary mailbox. Microsoft states newer versions can import older .nk2 files.
What if the List Stops Saving Names?
Microsoft states the cache can become corrupted and stop saving new entries. Remove entries one at a time first. Then clear the list with File, Options, Mail and Empty Auto-Complete List if the problem remains.
Related reading: how to restore deleted Outlook contacts and why Outlook email addresses go missing.
Frequently Asked Questions
Can I Restore the AutoComplete List?
Microsoft describes no restore feature. Email the contact again and Outlook adds the entry.
How do I Clear the AutoComplete List?
Open File, Options, Mail and select Empty Auto-Complete List.
How Many Names are in the List?
Microsoft states 1,000 entries in Outlook for Microsoft 365, 2019 and 2016.
Where does Outlook Store the List?
Outlook 2010 and later store it as a hidden message in the primary mailbox.
Key Takeaways
- Outlook creates the AutoComplete list when you send mail.
- Emailing a contact again restores the entry.
- Microsoft describes no direct restore feature.
- Outlook 2010 and later can import older NK2 files.
- Corrupted caches can stop saving new entries.
Sources and References
Facts follow Microsoft Learn.
- The Outlook AutoComplete list (Microsoft Learn) learn.microsoft.com