NextCloud’s mail client automatically marks emails by importance, so we disable it.
I recently set up NextCloud’s webmailer. In the process, I noticed that mails were automatically marked as Important. As a result, they also appear marked in red in Thunderbird.
I find this rather annoying, especially as the classification doesn’t work so well now either. However, the setting can easily be deactivated in NextCloud. To do this, we go to the “Mail Settings”. Then we deactivate the automatic classification.