Mapping Outlook email boxes to Thunderbird

To resolve the issues you're experiencing with Thunderbird not fully syncing Outlook mailboxes to Gmail, follow these detailed steps:

1. Ensure IMAP is Enabled:
   • In both Outlook and Gmail, make sure that IMAP is enabled. For Gmail, go to Settings > Forwarding and POP/IMAP and ensure that IMAP is enabled. In Outlook, check your account settings to confirm that it is set up to use IMAP.
2. Set Up Thunderbird with IMAP:
   • When adding your Outlook and Gmail accounts in Thunderbird, ensure you select IMAP as the account type. This allows Thunderbird to sync folders and emails properly.
3. Folder Mapping:
   • In Thunderbird, you may need to map the folders correctly. Right-click on your Gmail account in Thunderbird, select Subscribe, and ensure that all relevant folders (like Sent, Junk, and Deleted) are subscribed and visible. You can also check the Properties of each folder to ensure they are mapped correctly to the corresponding Gmail folders.
4. Check for Duplicates:
   • If you see duplicate folders or emails, it might be due to incorrect settings. Make sure that you are not creating multiple copies of the same folder in Thunderbird. You can remove duplicates by right-clicking on the folder and selecting Delete if they are unnecessary.
5. Adjust Gmail Settings:
   • In Gmail, ensure that the folders you want to sync are not excluded. Sometimes, certain folders may be set to not show in IMAP settings. Go to Settings > Labels and check the settings for each folder to ensure they are visible in IMAP.
6. Manual Cleanup:
   • If specific folders like Sent Mail, Junk, or Deleted continue to fill up, consider manually cleaning them out. You can also set up rules in Thunderbird to automatically manage emails in these folders based on your preferences.
7. Check Thunderbird Settings:
   • Go to Account Settings in Thunderbird and check the synchronization settings. Ensure that it is set to keep messages for offline use if needed, and adjust the settings to fit your requirements for how emails should be downloaded and stored.
8. Consult Support:
   • If the problem persists, consider reaching out to the Thunderbird support community or forums for more tailored assistance. They may have specific solutions for your version of Thunderbird or additional troubleshooting steps.

By following these steps, you should be able to better manage your email synchronization between Outlook and Gmail using Thunderbird. If you continue to face issues, further investigation into specific settings or configurations may be necessary.

References:

• Troubleshooting issues with IMAP mailbox migration

Hi. I'm Brian and I'll try to help.

This forum is dedicated to using Outlook.com with a web browser. Is that what you're doing? If that's the case, Outlook doesn't download anything. It is the mailbox itself. If you want the data in that mailbox to forward to Gmail when it enters the Outlook.com mailbox, then just set up forwarding in the Outlook.com settings here: https://outlook.live.com/mail/0/options/mail/forwarding. No need to involve Thunderbird at all.

It seems you may be confusing folders with mailboxes. Folders in Outlook.com are all part of the same mailbox. If you use a mail client to access that mailbox with IMAP or Exchange protocol, then anything in the mailbox will appear in the client.