Flooded with emails saying [PIA] A discussion was flagged

Haloan

I thought this board was dead, deactivated. 
Today I got hundreds if not more emails from this board about "[PIA] A discussion was flagged".
I did not have preferences set for this. 
What is going on?! How do I stop it?! 

Omnibus_IV

It should have stopped this morning. We found who was the sender and banned them. If you are still getting them, please tell me who is sending them.