Hello Cricktor
It seems the spam filter in question is Proton Mail's itself, not ours. Proton Mail sometimes rejects outgoing emails for suspecting it might be a spam that their user sends.
We'll contact you privately in due time (before the rewards are distributed).
Hello @eXch Support please note that I had the same issue that Cricktor had.
Some emails didn’t go through.
Here is a sample screenshot of the issue:
