Installation of eGroupware (How To)

By playing around with EGroupware - focus on mail - it looks like, that I can not search across multiple folders.

This is a function I’m using nearly every day - and should be a basic function from my point of view in all mail clients (Kopano, Outlook, Thunderbird …).

Am I missing a configuration or is this still not given with EGroupware?

FYI: I found in the net an article from 2022 where someone asked the same question. Answer was - it is on the ToDo list with high prio.

Thank you in advance