When I click on a mailbox that contains unread messages, and the list of its messages is displayed, it should be possible to start using navigation keyboard shortcuts (next/prev new message) immediately -- without having to click on/select a message within that mailbox.
What version is that? If it's from git, what exact commit is it? https://gerrit.vesnicky.cesnet.cz/r/809 fixed this.
Right, I installed from source and can confirm it works as expected.