The Config Editor contains some hidden preferences for more advanced usage.
How to open the Config Editor
- Open the Config Editor window.
* (Mac) Preferences > Advanced > Config Editor
* (Windows) Tools > Options > Advanced > Config Editor
- Click the I'll be careful, I promise button.
- Paste the preference you are looking to change into the Filter text field.
NOTE: You will need to paste in the exact preference name into the Filter text field. Postbox does not support open browsing of the hidden preferences.