Lost Email Contact Lists when reverting back to Outlook Legacy

Hi @Dave Smardon,

Welcome to the Microsoft Q&A forum.

I understand that you recently tried using New Outlook and then switched back to Outlook (Legacy). However, after reverting to Outlook (Legacy), you noticed that your contact list is missing.

At this point, to determine whether your contact list has been completely removed or if this is related to a synchronization issue, please help me confirm the following:

• Sign in to https://outlook.office.com and check whether your contact list is still visible there.

Additionally, you can try the steps below to see if the issue can be resolved:

Step 1: Open Outlook > Settings > Accounts

Step 2: Select the account that is experiencing the issue, then click the minus (–) icon to sign out of the account

Step 3: Close Outlook completely, then sign back in to the account

Based on the information you provide, I will be able to offer the most appropriate and effective guidance.

I look forward to hearing back from you.

 I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this.   

Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.

I look forward to continuing the conversation.

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In this scenario the contact lists are most likely still in the mailbox but not visible in the Legacy (classic) Outlook client, or they may have been deleted when switching versions. Use these checks and recovery options:

1. Check contacts and lists in the version that still has them
   • If the contact lists still appear in new Outlook or Outlook on the web, they are stored as cloud contacts.
   • In that case, continue to manage and send mail to those lists from the client where they are visible, or export/import them into Legacy Outlook (for example via .csv or .pst as described in the referenced Q&A) rather than assuming they are gone.
2. Look for deleted contact lists in new Outlook If the lists were deleted while using new Outlook, they can often be restored:
   1. In new Outlook, open People from the navigation pane.
   2. Select the Deleted folder.
   3. If the contact lists are there, select them, right‑click, and choose Restore.
   4. If they are not there, in Deleted select Recover deleted at the top of the list.
   5. Select the contact lists and choose Restore.
   6. Restored contacts/lists go back to their original folder when possible; otherwise, they go to the default Contacts folder.
3. Look for deleted contact lists in Outlook on the web/Outlook.com If the account is also used in Outlook on the web:
   1. From the navigation pane, select People.
   2. In People, select Deleted.
   3. Find and select the contact lists, right‑click, and select Restore.
   4. If not present, in Deleted select Recover deleted at the top.
   5. Select the lists and choose Restore.
   6. They will be restored to the original folder or the default Contacts folder.
4. Recover from Recoverable Items (classic Outlook on Windows) If the same mailbox is also configured in classic Outlook on Windows and the lists were hard‑deleted there, they may be in the Recoverable Items folder:
   • Use the Recover Deleted Items feature from the Deleted Items folder, select the contacts, and choose Restore Selected Items. Recovered contacts go to Deleted Items, from where they can be moved back into Contacts.
5. If contacts were in a local data file If the contact lists were stored only in a local Outlook data file (for example, a .pst) that is not currently attached to the profile, locate and re‑attach that file:
   • Search for .pst files (for example under C:\Users<YourUsername>\Documents\Outlook Files\ or C:\Users<YourUsername>\AppData\Local\Microsoft\Outlook\ on a Windows machine that previously held the data) and open them in Outlook via File > Open & Export > Open Outlook Data File.
   • Once opened, the contacts and lists in that file will appear under its Contacts folder and can be used or copied into the current Contacts.

If the contact lists cannot be found in Deleted/Recoverable folders in any Outlook client and there is no backup data file containing them, they have likely been permanently deleted and cannot be restored.

References:

• Restore or recover a deleted contact in Outlook
• How do I recover my old email messages, my contacts and everything else I had in Outlook? - Microsoft Q&A
• Outlook contacts not showing in "new" outlook - Microsoft Q&A