You can right-click and select "Inspect Element" to open the built-in Inspector with this element selected.

• https://developer.mozilla.org/en-US/docs/Tools/Page_Inspector/How_to/Examine_and_edit_HTML

You can check in the Rules tab in the right panel in the Inspector what font-family is used for selected text. You can check in the Font tab in the right panel in the Inspector what font is actually used because Firefox might be using a different font than specified by the website.

• https://developer.mozilla.org/en-US/docs/Tools/Page_Inspector/How_to/Edit_fonts

Hello,

when I do a right click I do not get "Inspect element"; all I see is "Inspect (Q)". When I click on that I do get a screen similar to your first link but the right hand side has no "Rules" tab.

Also I am not really interested to know the font that is used; I know it is wrong and it is not what I want. My question was how to change the font.

Kind Regards,

So, do I see that correctly, on the whole mozilla support forum there is not a single person that knows where the default font is and how to change it?

With this italic font it is basically impossible to distinguish read/unread emails. This does not happen with other browsers, so it is definitely a firefox problem. I'd hate to leave firefox; I have used it for years but it looks as if I have no choice.

This is likely a problem with the font that Firefox tries to use, but this font isn't working for some reason and Firefox switches to another (italic) font. The default font should be set in the Linux (GTK+/Qt) settings, so you can try to set a different font there.