How to change font size on incoming and outgoing email

Use keyboard shortcust:

Ctrl + = Ctrl + -

- go to TB menu > Settings > General > Language & Fonts > Fonts > click 'Advanced' button

- at the top, set 'Fonts for:' to Latin if it isn't already

- change Proportional and Monospace fonts/sizes to your liking

- set Minimum font size to 14, or lower if you want a small font size

- at the top, change set 'Fonts for:' to Other Writing Systems

- repeat the process of changing fonts/sizes

- at the bottom, make sure 'Allow messages to use other fonts' is disabled if desired > OK > close the popup