Thunderbird – Useful Extensions

Theme Font & Size Changer
Gnome3 DE Settings: Size = 13, Zoom = 1.50
Hi DPI screens – in MacBookProRetina11,1 – 13″ – Thunderbird often gives odd rendering of the screen font sizes.
On Gnome3 – everything is too big!  On OSX – everything is too small!

TT DeepDark Theme
Get to a dark theme to match (more or less) Gnome3 dark theme.