Outlook Classic will not connector to Yahoo email without using the APP password.

Question

I am using Outlook Classic on a new windows 11 computer. My email account is with Yahoo. I am having multiple problems with getting Outlook setup to sync to the Yahoo email. So I deleted my email account from Outlook Classic and started over. I was unable to get my "new" outlook account to login to Yahoo Email - but stumbled onto the "one time" APP password requirement. Got that working, but it is not a "one time" thing. I had to add that APP password into the account settings "login" boxes. Now it logs in without issue. However, as soon as I open Outlook Classic, it automatically logs in. I read that Microsoft has fixed this, but I was unable to find the details.

After getting Outlook to login to Yahoo Email, it downloaded all of my Yahoo Email INBOX messages (8,821 emails). No need to bore anyone as to why such a large number. Before hitting the "Send/Receive" button the first time, I changed an account setting so that Outlook would only sync my INBOX and also unchecked counting unread messages. Hit the "Send/Receive" button, I checked the tasks, and "sending" was quickly accomplished, however synchronizing "inbox" has been running for almost 30 minutes.

It is still running and I don't know if that is a problem or just due to the large number of emails that have to be sync'd. I tried to end the task, but it continues to indicate "Synchronizing "inbox" at the bottom of the Outlook window.

Any help would be appreciated.

Regards,

Frank

Answer 1

Dear Frank DiJoseph 

Thank you for reaching out to the Microsoft Q&A Community. I understand you're having difficulty syncing your Yahoo email account with Outlook Classic on your Windows 11 computer. I'm happy to assist you. Please kindly follow these steps :   

1. Yahoo App Password Requirement  

Yahoo requires an app-specific password for third-party email clients like Outlook due to enhanced security protocols. This password is not a one-time use—it must be entered and saved in your Outlook account settings.  

To generate and use a Yahoo app password:  

• Sign in to your Yahoo account via a web browser.  
• Go to Account Security.  
• Select Generate app password.  
• Choose Outlook Desktop or a similar option.  
• Copy the generated password and paste it into Outlook’s login settings.  

This password must remain in your Outlook configuration to maintain access.  

2. Outlook Auto Login Behavior  

Outlook Classic is designed to auto-connect to configured accounts upon launch. If you prefer manual control:  

• Open Outlook.  
• Go to File > Account Settings > Manage Profiles.  
• Choose Prompt for a profile to be used.  
• Restart Outlook and select your profile manually.  

This won’t disable auto-login but allows you to choose when and how to connect.  

3. Synchronization Delay with Large Inbox  

Syncing over 8,800 emails can take time, especially if attachments are involved. Here’s how to optimize performance:  

• Go to File > Account Settings > Account Settings.  
• Select your Yahoo account and click Change.  
• Adjust the Mail to keep offline slider to a shorter duration (e.g., 1 month).  
• Uncheck Download shared folders and Use Cached Exchange Mode if not needed.  
• Click Next, then Finish, and restart Outlook.  

4. Monitor Sync Progress  

To check if syncing is stuck or progressing:  

• Click Send/Receive > Send/Receive Groups > Define Send/Receive Groups.  
• Select your group and click Edit.  
• Ensure only the Inbox is selected for syncing.  
• Monitor the Outlook Status Bar or press Ctrl + 6 to view the Sync Issues folder.  

If the sync continues for hours without progress, consider:  

• Restarting Outlook.  
• Rebuilding the OST file by closing Outlook and deleting the file from %localappdata%\Microsoft\Outlook.  

5. Verify IMAP Settings  

Ensure your Yahoo account is configured with the correct IMAP settings:  

• Incoming server: imap.mail.yahoo.com, Port: 993, Encryption: SSL  
• Outgoing server: smtp.mail.yahoo.com, Port: 465 or 587, Encryption: SSL/TLS  
• Use the app password for authentication.  

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Warm regards  

Answer 2

Hi Frank DiJoseph, 

It is my pleasure to hear that our response helped resolve your issue. Is there anything else I can assist you with? If not, please feel free to let me know so I can close this thread. 

Have a nice day !

Warm Regards