Erscheinungsbild

Doku siehe http://kb.mozillazine.org/Category:Visual_customizations_%28Thunderbird%29 und https://www.eriwen.com/css/tweaking-thunderbirds-chrome/

Verzeichnis Chrome erstellen

darin userChrome.css erstellen. Formatierungsbeispiele:

/* Global UI font */
* { font-size: 11pt !important;
font-family: Verdana !important;
}

Trees individuell

#folderTree > treechildren {font-size: 12px; font-family: Arial;}
#threadTree > treechildren {font-size: 12px; font-family: Arial;}
#dirTree > treechildren {font-size: 12px; font-family: Arial;}
#abResultsTree > treechildren {font-size: 12px; font-family: Arial

Menüs

/* Menu font */
menu, menulist, menuitem {
font-family: Times New Roman !important;
font-size: 12pt !important;
}

Konfigurations-Optionen

http://kb.mozillazine.org/About:config_entries