Some email clients have multiple rows of information in that column - the first row might have name & subject, the next row might show the first two sentences of the email. Or it might have the subject on a separate line, so the column can be kept narrow but still show the full subject line.
Think of the iOS Mail or Android GMail interfaces, for example.
Or outlook 2003 https://www.microsoft.com/middleeast/office/images/editions/... which was released like 15 years ago. I remember because I made an office 2003 theme for thunderbird. I am never touching that 1500 CSS files clusterfuck again.
It's not doable with CSS only anyway, so it won't happen if they just design a new theme on the current XUL toolkit (correct me if anything changed about that lately).
This entire discussion is not about complex interface design and the lack of technical solutions, but the stagnating product. And about questionable actions to give it a peppy appearance.
[1] https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queri...
Reported: 15 years ago Modified: 28 days ago
How the years go by.
edit: https://wiki.mozilla.org/Talk:Thunderbird:2.0_Product_Planni... Users were talking about it for the 2.0 release.
From what I gather it uses some of thunderbird and firefox code but is heavily modified and is proprietary software.
Too bad they decided to drop linux support, it renders it useless to me.