As it so happens, I answered this request just yesterday. Several steps and do not pass up any of them.

Okay, this may sound strange, but here is the real way to set fonts on Thunderbird. And I attached examples of my own setting of Calibri 14 as my default. Here goes: - in Tools>settings>general, set your default font. - then click the advanced button. Notice the drop-down menu at top. It probably says 'latin' or 'other writing systems' - this is IMPORTANT: set your desired font settings in one, and then set the IDENTICAL settings in the other. In attached screenshots you will see my latin and otherwritingsystem match. Notice I also set monospace font. - and, if you have account set to compose HTML, then set that in tools>settings>composition to variable-width and medium font. Your selected font in prior steps will show. (You would only change the HTML font setting if your intent is for recipient to receive your preferred font - not my personal recommendation.) - Set Sending Format to 'automatic'

With these settings, your compose window and your sent folders will match. And if you don't write HTML, none will be sent . If you do these settings once, your font will always be consistent.

Font size of 14 is small, but I like it. I suggest you try 20 for a start.

Hi David - thankyou for the response. However I'm afraid I can't see your screenshots clearly enough to check this out. I did follow your instructions for the first part (i.e. under the settings option, I selected calibri and font 16 - as a trial to see how much bigger that would appear on my screen - then advanced and again as you said, Latin was the default on that page, I put the font size at 16, then I hit a brick wall! You say' and then set the identical settings in the other' - in the other WHAT? The variable and medium are set as you instructed. Where am I going wrong?

The other menu option besides 'latin' is 'otherwritingsystems' - Make sure both are identical.

Hi - thanks again. I only have ONE dialog box when I click on advanced after setting the required font details. I dont know/havent got another dialog box to make sure BOTH(?) are identical. Sorry, but as you can tell I am quite new to this, I have taken a screenshot of my screen - the one that comes up when ADVANCED is selected. I hope this attaches to this reply so you can see what I mean

https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2022-09-26-03-41-58-3c643d.png

At the top of your screenshot it says Fonts for Latin. That is a drop-down menu. Click it and scroll down to and select 'otherwritingsystems.' I also encourage setting minimum font size to something other than 'none'

I am so sorry I'm stupid - and an annoyance, have tried again and am attaching screenshots of both of the pages I have on my screen, set the font to 20 now, still not changing from the much smaller original font.

Your earlier screenshot of Latin was different. Please review both to be the same. Post both latin and otherwritingsystems.

These 2 screenshots are of the same screen, at different times i.e. when I changed defaults. I only have ONE screen available when I access it from the main thunderbird menu. This one screen I have changed as suggested, trying different options and then going back to see if it made a difference to the emails - neither of them did! When you are saying 'make both identical' - I dont HAVE 'BOTH' - only one!

I am puzzled at the complexity you're experiencing. The settings for Latin need to be the same for Otherwriting systems. Do a screenshot when Latin is selected and then another screenshot when Otherwritingsystems is selected.

2 screenshots attached, did one with latin selected, then changed the options to other writing systems and did that screenshot. As I said earlier, I only have access to ONE set of options when I select Advanced.

OK, I'll try again. - Select 'Latin' and set fonts and font sizes and then click OK, - Next, select 'Otherwritingsystems, set fonts and font sizes to be IDENTICAL to what you set for Latin. And then click OK. NOW do two screen shots and they should be identical. Also, that selected font should now appear for your messages

Well - at last I am getting a bigger font size!! Dont quite know how it happened, but it has! Thankyou very much for all your help - it really is greatly appreciated!

Regards - Sheila

You are welcome. My assumption is the two settings now match. That's what made it work.