Hello

I am with 102.4.2 on Kubuntu 22.04 and I have never seen something like that. Also, there is something strange in the selection of your screenshot; in my Thunderbird, when selecting a mail the whole line is highlighted, while in your screenshot only the first column is highlighted. Maybe at some point the view was customized ? is there a chrome subdirectory in your profile directory ?

Thanks for looking into this. The behaviour is the same independent of my having a chrome subdir or not ( I usually have a userChrome.css, but this doesn't affect the issue). Also, I am not quite sure what you mean with "only the first column is highlighted"?

In your screenshot, the first column is in white characters, red background, the second column is in black characters, white background . In my Thunderbird, with standard theme (did you change the theme ?), the whole selected line is in white characters, blue background, and the other not selected lines are all in black characters and white background. There are other peculiar things: the 2 columns are not quite at the same horizontal level, and the first column appear sorted, however there is a sort indicator for the second column (AFAIK it's not possible to sort for 2 columns by clicking on the headers), but at the wrong place (left instead of right). Very strange.

All that might have to do with my userChrome.css, which I had in place when taking the screenshot. I have the feeling that the problem lies somewhere else. I have been staring at the debugger for quite too long now, at the file msgHdrView.js. From what I have understood so far:

gExpandedHeaderView['from'] is updateHeaderValue

If I manually change that in the console

gExpandedHeaderView['from'].outputFunction=outputEmailAddresses

I get headers again. From that I take that it has nothing to do with styling...

Update: after installing https://addons.thunderbird.net/en-US/thunderbird/addon/userchromejs-2/ to make sure I can load userChrome.js, I but said line into it:

gExpandedHeaderView['from'].outputFunction=outputEmailAddresses;

Suddenly, I have from headers again. Now, I only need to understand what is actually causing this...

Turns out the interesting lines are 297 and 310, which ask for the config settings of mailnews.headers.extraExpandedHeaders and mail.compose.other.header. The later had set "From" as the value, and that caused the "from" header to have the wrong output function (in the end). So mail.compose.other.header it was.