Always tags messages from myself as "important"

Expected behavior

Messages from myself in the inbox should not always be tagged as "important"

Actual behavior

They are. Every single time. I should say that I have configured thunderbird, which is my default mail client to save the copy of the sent mail in the folder of the original mail, so if the latter is in the inbox, the response is also saved in the inbox. And for some reason, nextcloud mail always thinks that this mail must be really important. I have untagged it many many times already, but it seems to have zero learning capabilities.
(For untagging I use thunderbird, for me, nextcloud mail is more something that I play around with from time to time)

Mail app

Mail app version: (see apps admin page, e.g. 0.5.3)
1.10.5

Mailserver or service: (e.g. Outlook, Yahoo, Gmail, Exchange,...)

Dovecot

Server configuration

Operating system: (e.g. Debian 8)

Ubuntu 20.04

Web server: (e.g. Apache, Nginx,...)

Nginx

Database: (e.g. MariaDB, SQLite or PostgreSQL)

Mariadb

PHP version: (e.g. 7.0)

7.4-fpm

Nextcloud Version: (see admin page, e.g. 13.0.2)

22.02

Client configuration

Browser: (e.g. Firefox 48)

Firefox 91

Operating system: (e.g. Arch Linux)

Manjaro

The report names no source file, test, or entry point. Reproduce the setup with Nextcloud Mail 1.10.5, Dovecot, and Thunderbird saving sent replies in the inbox, then trace how messages from the account owner receive the important tag. Done means those messages are not always marked important and existing untagging behavior is respected.