Outlook upgrade bad

Question

How can I revert to my previous Outlook . The new one lost my address book and has no junk mail blocker

Answer 1

Hi @edward yatscoff,    

Welcome to the Microsoft Q&A forum.    

Thank you very much for reaching out regarding the issues you’re seeing in the new Outlook. I appreciate your patience and the details you provided. 

I'd like to provide the following information: 

A - What’s happening 

Contacts / Address Book: New Outlook only syncs cloud‑based contacts (Microsoft 365 / Outlook.com). If your contacts were previously stored locally in classic Outlook such as under “This Computer Only” or in a .PST file they won’t automatically appear in the new Outlook. You’ll need to export them from classic Outlook and import them into your cloud account to make them visible again. 

Junk mail controls: The new Outlook has removed the traditional Junk Email options you may be familiar with. Spam filtering now happens server‑side, and you manage Safe senders / Blocked senders through Outlook on the web, or via the Junk email settings if they appear in the New Outlook’s Settings.  

B - Recommended next steps 

1/ Bring your contacts into the new Outlook 

1. Open Outlook (classic) on your PC, go to File > Open & Export > Import/Export > Export to a file > CSV, and choose your Contacts folder to export. Save the CSV file.  
2. 
3. In the new Outlook, switch to People (or in a browser go to Outlook on the web), choose Manage contacts > Import contacts, and upload that CSV. Your contacts will sync and then appear across the new Outlook experience. 
4. 
5. Note: If those contacts were stored locally and you no longer have the original PST or any backup, they unfortunately cannot be recovered unless you can locate the old data file. 

Additionally, if you’re unsure whether you still have Outlook (classic) installed, you can temporarily switch back using the toggle in the top‑right of the new Outlook window, export contacts, and then switch forward again. 

 

2/ Control junk mail (block/unblock senders) 

Open Outlook on the web > Settings > Mail > Junk email. Here you can add Safe senders and domains (to keep wanted messages out of Junk) or Blocked senders and domains (to send unwanted messages straight to Junk). These settings take effect immediately in the new Outlook as well. 

3/ Switch back to Outlook (classic) 

You can switch back to Outlook (classic) at any time via the toggle in the top‑right of the new Outlook. If the toggle isn’t visible, it usually means classic Outlook isn’t installed; Microsoft’s article shows options to restore it.  

For additional information, you can refer to this article: Toggle out of the new Outlook for Windows - Microsoft Support 

I hope this information is helpful. Should you have any further questions or need additional assistance, feel free to reach out.     

I look forward to hearing your thoughts on this. 

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Answer 2

To go back to the previous (Classic/Legacy) Outlook and regain features like your address book and junk mail controls, follow these steps based on the Outlook platform in use.

1. If using Outlook for Mac (New vs Legacy Outlook)

1. Open Outlook.
2. On the menu bar, select Help.
3. Select Revert to Legacy Outlook.
4. If prompted to Try the New Outlook, choose Not Now.

Notes:

• Accounts added in New Outlook for Mac are not automatically added in Legacy Outlook, and vice versa. After reverting, re‑add any accounts that are missing.
• Legacy Outlook includes the traditional address book and junk mail features.

If the issue started after trying to upgrade from Outlook 2016 for Mac to the “Free” Outlook from the App Store and you are stuck or missing data, use the full revert procedure:

1. Revert to Legacy Outlook (as above).
2. Export local folders (On My Computer):
   • In Outlook, select Tools > Accounts.
   • Select each account and click the minus (-) button to remove all accounts.
   • Select File > Export.
   • Check all item types and select Continue.
   • Save the archive file somewhere easy to find.
3. Reinstall Outlook 2016 for Mac:
   • Control‑click the Outlook app icon and select Move to Trash.
   • Download Outlook 2016 or Office 2016 (which includes Outlook) using the provided installers.
   • Install Outlook 2016.
4. Clean old profile data before first launch:
   • In Finder, select Go > Library.
   • Open Group Containers.
   • Delete any folders that start with UBF.
   • Start Outlook 2016 and import the archive file you exported.

This restores the older Outlook experience, including your address book and junk mail handling.

2. If using Outlook for Windows (New Outlook vs Classic Outlook)

The context provided here only covers how to control junk mail in New Outlook for Windows, not how to switch back to Classic on Windows. However, New Outlook does support junk mail blocking:

1. Open new Outlook for Windows.
2. If multiple accounts exist, select the account to configure.
3. Go to Settings > Mail > Junk email.
4. Under Blocked senders, enter email addresses to block and select Add.
5. Under Blocked domains, enter domains to block and select Add.
6. Select Save.

Blocked messages go directly to Junk Email and are automatically removed after 14 days.

To prevent wanted messages from going to Junk, add trusted addresses as Safe Senders as described in Add recipients of my email messages to the Safe Senders List.

If the address book appears empty in New Outlook, verify that the correct account is selected and that contacts are stored in that account; New Outlook and Classic Outlook may not share all local data.

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References:

• How to revert back to Outlook 2016
• Outlook for Mac
• Missing toggle button in Outlook for Mac
• Block or unblock senders in Outlook