Hello there Dwilhelm.

Technical Support: Thunderbird Connection Issues This indicates a communication error between thunderbird.exe and the mail server. This is often caused by a hung process within the system or the software itself.

1. Basic Troubleshooting

Have you tried restarting Thunderbird? Completely close the application and reopen it. Additionally, check if Offline Mode is active:

Look for the icon (two small computers) in the bottom-left corner.

If there is a red "X" over the icon, you are working offline.

Click the icon to toggle back to Online Mode.

2. Check for Zombie Processes

Check for any hung processes. When closing Thunderbird, "zombie processes" can sometimes remain active in the background, preventing the application from establishing a new connection. Restart your computer to ensure all instances of the software are fully terminated.

3. Review Account & Security Settings

If the issue persists, please check your SMTP and Server Settings:

Ensure that "Check for new messages at startup" and "Check for new messages every X minutes" are enabled.

Clear your password cache: Providers occasionally update their authentication methods (e.g., switching to OAuth2). Cached credentials can conflict with these new security protocols, causing the connection to fail.

If the steps above failed, please use the global database to rebuild the involved data. https://support.mozilla.org/en-US/kb/rebuilding-global-database

I followed these suggestions, and now Thunderbird is downloading emails -- but they're not appearing in the Inbox, or anywhere else. I can see them on webmail, but not on the app.

Hello there

Since the downloads are visible in the web app, it’s possible the desktop software is glitching or the view settings have changed. We can start with a 'soft' fix by repairing the folder. Right-click the Inbox folder, select Properties, and on the General Information tab, click Repair Folder. Don’t worry, your emails will remain safe. Fix this Alternatively, check your view settings. Go to the View menu and select Messages. Ensure All is selected. If 'Threads with Unread' is active, most of your mail may be hidden. , <Ensure that All is selected. If "Threads with Unread" or "Watched Threads with Unread" is selected, most of your mail will disappear.> .

Use Change the protocol from POP to IMAP. The issues you're seeing in Thunderbird suggest that using POP on the desktop may have triggered a server-side conflict

Tip Verify your Thunderbird download location: Settings > General > Files & Attachments > Save files to..