The signature separator in Mozilla Thunderbird is a double dash i.e. “–” which is kinda asymmetric in my view, if not call it ugly! But there are a few simple steps that you can remove that as follow.
- Go to Preferences>>General>>Advanced Configurations
Press “Config Editor…” button and promise that you will be careful changing the config files.
Search for “signature_separator” and click on it to switch false to true.