Extra compact view for a better overview

Is your feature request related to a problem? Please describe.

For me, the Nextcloud's mail app needs unnecessary much space to display the mails overview - even in the compact view (horizontal layout).
E.g. compared with Snappymail, I can see on the same height of my nextcloud window only 4-6 mails (with Mail) against 10 mails (with Snappymail).
The reason for this, that there are fancy (but not urgently necessary) separators like "today", "last week", etc.
Also, for each mail it is not only a single line in the style "Sender - Subject - Date", instead always two lines are required (1: Sender - Date, 2: Subject).

Describe the solution you'd like

I'd like to have an "extra compact" view for the mail overview:
Exactly one line per mail (Sender, Subject, Date), no extra spacing between the lines, no extra separators ("today", "last week"...).
The layout of Snappymail might be seen as blueprint for it...

The same is true for the list of folders. For me it should be more compact, no extra spacing.

Describe alternatives you've considered

I am using Snappymail - however this project is currently no longer really active, thus I am looking for an alternative. Nextcloud's Mail is very nice from the feature set, however the layout is the thing that stops me from using it as preferred Nextcloud Mail agent.

Additional context

No response

The issue does not name files, tests, or entry points. Start by locating the mail overview and folder list UI, then determine how an optional extra-compact layout could show one line per mail without separators or extra spacing. Done means the compact layout displays sender, subject, and date on one line and makes the folder list more compact.