Thunderbird 102* has now added an easy way to increase the font size of Folder names in Folder Pane and list of emails in Thread Pane.

Via 'Menu icon' (3 lines):

• 'Menu icon' > 'View'
• For 'Font size' click on the + sign

Via top 'Menu Bar' toolbar:

• 'View' > 'Font Size' > click on 'Increase Font Size'

If you are looking to increase the font size generally throughout all of Thunderbird then there is a way via the 'Config Editor'.

To access 'Settings' use any of these methods:

1. Bottom of 'Spaces Toolbar' on left side - click on the gear wheel icon
2. 'Menu icon' > 'Settings'
3. Via Menu Bar toolbar - 'Tools' > 'Settings'

• Select 'General'
• Scroll to bottom and click on 'Config Editor' button

It will offer a friendly warning : )

• In top search type: pixels and Look for this line: layout.css.dev.PixelsPerPx

The default value is a negative number: -1.0

• click on the far right pencil icon - it allows you edit
• completely remove the negative number
• now type a positive number such as 1.20 or 1.25 or 1.5

Always start with the lowest number and slowly increase. Do not enter a large number as you may discover the font is so large you cannot access anything. Whilst this can be fixed, it is more complicated as you have to access profile folders and edit the 'prefs.js' file - you need to know what you are doing.

IF by any chance you are using a MAC OS then you may find you do need to increase the pixels because a MAC starts with a much smaller pixel size than a Windows OS, so start at 2.0 and then try 3.0 gradually increasing.

• The pencil icon has now changed to a 'tick icon - click on the 'tick icon' to save.

You will instantly see it's effects, so you can keep that tab open and edit again if you need to adjust results.

See image below as a guide.