I use what I believe is the Thunderbird default display screen layout. A folder list is shown down the left side of my screen - about 1/5th of the screen width. To the right of this, the rest of the screen includes a list of messages in the top portion and in the lower portion a displayed the contents of a message selected in the Message List above. My question concerns the lower (Message Display?) in the lower portion. How can I change the font style and size in the message display section? I've searched everywhere for a font default or option. My messages appear in a tiny serif font (Times?) whereas the other two sections (Folder list and Message list) are in an acceptable non-serif font. I do have the Theme Font and Size changer add-on installed but any changes in its settings do not affect the Message Display. Is there an option somewhere I need to change? Thanks, Dave