>>TazeTS+(OP)
This is happening to me too.

I suspect the recipient email address they're using (which I don't share widely) might have been exposed in one of Discord's recent support breaches, because I can't work out where else they could've got it from.

I'm using Proton Mail, so I set up a Sieve filter [1]. I'm doing this because this email address isn't used for anything even remotely related to Zendesk. I mostly use a separate custom domain address for everything.

[1]: https://gist.github.com/hampuskraft/7325ba2ad23a9445ebd93c64...

>>TazeTS+(OP)
Yes, sadly they are legitimate emails so its hard to block them. The problem seems to be on zendesk side where they are accepting any email as the source of the ticket and simply replying to that email with the contents of the ticket.

Apparently they are well aware of this problem since at least last year:

https://support.zendesk.com/hc/en-us/articles/9833274501786-...