How to Fix Outlook Cached Contacts Disappeared Issue?

Why do Cached Contacts Disappear?

Microsoft names these causes of the Outlook cached contacts disappeared issue:

• Entry limit. Outlook for Microsoft 365, 2019 and 2016 store up to 1,000 entries. Outlook then removes names by usage weighting and some names disappear unexpectedly.
• Corrupted cache. A damaged list stops saving new entries.
• Option off. Suggestions stop when Use Auto-Complete List to suggest names is unticked.
• Exchange Online. Outlook for Microsoft 365 Version 2202 and later uses Microsoft Search for suggestions with an Exchange Online mailbox. Steps in this guide do not apply there except the option and the single entry removal.
• Separate list. Web mail has its own list that Outlook does not share.

Which Method Fits Your Account?

Open File, Account Settings and again Account Settings to see whether your Outlook profile uses a POP3, IMAP, Exchange or Microsoft 365 account. Then match that account type to a method for Outlook cached contacts disappeared cases:

5 Ways to Fix Outlook Cached Contacts Disappeared Issue

Outlook handles four fixes and software handles the fifth:

Method #1: Tick the AutoComplete Option (Free)

Name suggestions appear in the To, Cc and Bcc boxes only when the Auto-Complete option is ticked. Four steps check it:

1. Select File and Options.
2. Open the Mail tab.
3. Scroll to Send messages.
4. Tick the Use Auto-Complete List to suggest names box.

Note: Microsoft lists this as the only setting that applies to the Exchange Online case besides the single entry removal.

Method #2: Import an NK2 File (Free)

POP3 accounts store the list in an NK2 file on the computer according to Microsoft. Six steps import it:

1. Type %APPDATA%\Microsoft\Outlook in the Windows Search box and copy the NK2 file from the old computer.
2. Open Control Panel, select Mail and then Show Profiles.
3. Note the profile name.
4. Paste the NK2 file into the %APPDATA%\Microsoft\Outlook folder of the new computer.
5. Right click the file, select Rename and type the profile name.
6. Type outlook /importnk2 in Windows Search and press Enter.

Note: Microsoft states that Outlook 2007 and earlier saved the list in an NK2 file. Outlook 2010 and later import an older NK2 file.

Method #3: Restore the AutoComplete Message With MFCMAPI (Free)

Microsoft 365, Exchange and IMAP accounts store the list as a hidden message in the data file. You need an earlier MSG export of that message. Seven steps restore it:

1. Close Outlook and Outlook on the web on every workstation.
2. Open MFCMAPI and select Logon from the Session menu.
3. Select your profile and double click your mailbox.
4. Expand Root Container and then Top of Information Store or IPM_SUBTREE.
5. Right click Inbox and select Open Associated Content Table.
6. Delete the existing message with the subject IPM.Configuration.Autocomplete after you export it.
7. Select Folder, Import and From MSG and choose your earlier export.

Note: Microsoft warns that you must export the existing message before you delete it. Choose Load message into current folder in the Load MSG window. Exchange Online mailboxes on Version 2202 and later use Microsoft Search so this method does not apply there.

Method #4: Reset a Corrupted AutoComplete List (Free)

Corrupted caches stop saving new names. Microsoft advises removing entries one at a time first and clearing the list when that does not help. Five steps clear it:

1. Open Outlook and select File and Options.
2. Open the Mail tab.
3. Select Empty Auto-Complete List under Send messages.
4. Select Yes at the prompt.
5. Send mail to your contacts so Outlook builds the list again.

Note: Microsoft also documents the start switch Outlook.exe /CleanAutoCompleteCache for the same reset.

Method #5: Recover Cached Contacts With EmailDoctor Outlook Cached Contacts Recovery Tool

Names that Outlook already trimmed do not appear until you restore a copy. EmailDoctor Outlook Cached Contacts Recovery Tool opens AutoComplete cache files and NK2 files, and exports the contacts to PST and other formats. Auto-detection finds the storage location of the cache files.

Both Windows and Mac systems work with the software.

Add the Cache File

Copy the cache file first. Two steps add it:

1. Open the software and click Add File.
2. Browse to the NK2 or Stream_Autocomplete file or use the auto detect option and click Add.

Preview the Contacts

Preview lists the Display Name and Email Address of every contact. Tick the contacts you need.

Export the Contacts

Three steps save them:

3. Click Export.
4. Select the output format from PST, vCard, CSV, Google CSV, PDF, MSG or HTML.
5. Choose the destination and select Export.

What Goes Wrong With the AutoComplete List?

Review these Outlook cached contacts disappeared cases before you clear the list:

Frequently Asked Questions

Author’s Verdict

Tick the AutoComplete option first. Import an NK2 file or restore the hidden message when you have a copy.

Reset the list when Outlook stops saving names. Use recovery software when Outlook cached contacts disappeared and no copy exists.

Copy the cache files first and test one export before you rely on the result.