Trust level PMs should be turned off after reaching trust level again

So, I was demoted from TL3 to TL0, then promoted to TL2.
When I joined the forum, I got the initial TL1 and TL2 promotion PMs:

However, it seems that it has happened again:

I wish there was a way to disable these messages being sent more than once, it causes clutter. There should be a feature to disable these additional messages. It would just save PM clutter.