Thunderbird how can I increase text size for reading my messages?

I know age is a factor but my incoming messages are now so small that I can no longer readily read them.
I have spent some time searching for solutions but none have done what I seek.

I did have this sorted out a while ago (September 2018) but T’bird seems to have reverted to some default which does no longer works for me and I can no longer access about:config in T’bird.

Please can somebody enlighten me.

For me, it appears there’s two ways to adjust font size … or maybe I misunderstand what you’re hoping to fix - achieve. Two screenshots:
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tb1
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tb2

I am also seeing, for several month with thunderbird version 115, very very small fonts ( probably < 6pt) but only in the body of received messages; very annoying. This seems to only happen in messages that are only typed text. Typing a response to a text message also displays in the same tiny font. Received messages with a graphic image (ads) in them have normal font size. All other text in Thunderbird, aside from message window, is as set in general font settings.

The small font size can be increased manually by selecting the text and setting font settings to the largest size in the settings in the menu bars of message window. Written responses are then also in larger font.

Have posted this in a few sites with no response. Glad at least one other has seen this.

tom kosvic

I have found that the only way to view the message text without having to mess up all the other text in the headers etc is to use View>Zoom. This does at least give me readable messages but this is hardly a satisfactory solution. My problem is that there are just too many variables and settings which may be changed and some of these are conditional on needing html or something else. When somebody finds a decent solution please do post it as it is clear now I am not the only one with issues.
Thanks for the replies.
Budgie

Thunderbird 115.6.0, Leap 15.5.
For me CTRL-+ increases the message size temporarily. To set the size overall is as aggie posted above.

Actually it is CTRL+= (CTRL plus Equal key) . And CTRL+ - (CTRL plus Minus key) decrease the text size.

The settings presented by @aggie do not solve this issue of very small fonts in messages. They adjust the fonts elsewhere in the app. I have tried these several times and the problem keeps appearing.
tom kosvic