Everything about Thunderbird in 18.04 is right for me. The only thing that stands odd is the left sidebar icons which look very old.Is there any method to change this ? And use Font Awesome or Material Icons. Thanks.
Full themes are no longer supported in Thunderbird, but there is one icon theme that still works. It's Phoenity icons. However this is not based on Font Awesome or Material Icons.
Please don't mind, I add my alternate answer. Monterail Dark looks much finer than Phoenity icons and it is a full theme, a modern one. I will let users choose between the options. There is a darker variant as well which works on the latest version of Thunderbird v68.
Full themes are no longer supported in Thunderbird, but there is one icon theme that still works. It's Phoenity icons. However this is not based on Font Awesome or Material Icons.
Please don't mind, I add my alternate answer.
Monterail Dark
looks much finer thanPhoenity
icons and it is a full theme, a modern one. I will let users choose between the options. There is a darker variant as well which works on the latest version of Thunderbird v68.https://addons.thunderbird.net/en-US/thunderbird/addon/monterail-dark/
Don't go by the screenshot, Moneterail Dark is available for English as well.