Yeah, this is an issue I caused unintentionally while trying to make MorphMarket News posts as wide-reaching as possible.
I inadvertently set the status of the category to “tracking”, which sent EVERYONE an email for every comment made 
I have fixed this, but because I messed up so badly and sent it to everyone, there is a lot still in the queue to go out… so expect a couple more, but they will stop within a day or so.
I apologise for this 