These instructions are valid only for Thunderbird 152 and older. For Thunderbird 153 and newer, you will have to do the following steps in Firefox or whatever your system web browser is.
This usually happens when cookies are disabled in Thunderbird. To fix this, please enable cookies by following these steps:
- Click the Thunderbird menu ☰ > Settings Gear ⚙ icon > “Privacy and Security”
- Ensure "Accept cookies from sites" is checked.
- Set "Accept third-party cookies" to "Always".
If you would like to only enable cookies for Thundermail authorization while blocking other third-party cookies, please follow these steps:
- Click the Thunderbird menu ☰ > Settings Gear ⚙ icon > “Privacy and Security
- Ensure “Accept cookies from sites” is checked.
- Set “Accept third-party cookies” to “Never”.
- In “Web Content,” click “Exceptions…”.
- Enter ‘https://auth.tb.pro’ into “Address of website”and click “Save Changes”.
Restart Thunderbird and try adding your account again.
Still having trouble? Try using Thunderbird Troubleshoot Mode, or reach out to our support team for further assistance.