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How to change the font-size of Thunderbird thread list on a Mac?

I don't see any settings in the preferences.

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Set it up 11 intead and it will display better –  user64878 Jan 26 '11 at 18:31

2 Answers 2

You need to edit your userChrome.css.

Go to ~/Library/Thunderbird/Profiles/[yourProfileName]/chrome/ (creating the chrome directory if it doesn't exist) and edit userChrome.css, again creating if it doesn't exist.

For example, to edit all text in Thunderbird (except message view), enter the following:

/* Global UI font */
* { font-size: 18pt !important;
  font-family: Verdana !important; 

The result looks something like this:

alt text

Unfortunately, I was unable to find the CSS class for the message list. Replace the * in the css with that css class and it should work as intended.

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Yes, this example is exaggerated, but how else can I prove it works? –  Daniel Beck Jan 26 '11 at 18:30
This solution only helps a little bit, because you only increase the font - but you need to add space for that larger font as well. –  user111964 May 31 '12 at 13:43

Daniel's answer is correct. You have to extend userChrome.css. Here is CSS code that will fix the spacing as well:

/* set default namespace to XUL */

/* Set Font Size In Folder Pane */
#folderTree >treechildren::-moz-tree-cell-text {
    font-size: 12pt !important; }

/* Set Font Size In Thread Pane */
#threadTree >treechildren::-moz-tree-cell-text {
    font-size: 12pt !important; }

/* Set Height For Cells In Folder Pane */
#folderTree >treechildren::-moz-tree-row {
   height: 25px !important; }

/* Set Height For Cells In Thread Pane */
#threadTree >treechildren::-moz-tree-row {
   height: 25px !important; }
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