This might be old hat to the computer whiz kids here. There
is a add on for Firefox and Thunderbird that regulates font size.
Theme Font & Size Changer
The subject lines for Usenet posts were uncomfortable to read.
The size changer fixed that. I couldn't find anything in
Thunderbird preferences to fix that.
Useful ad on which I have.
Think it has been discussed in news.mozilla.org.
I often go there for help after exhausting my personal search.
I download Thunderbird, Firefox and general groups. Helpful folks there.
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