I don't really go after rep, it takes way too much effort and I have far too much actual rewards to counter. If you are using PeakD you can now completely filter the notifications with their new PeakD Notifications if you have it blacklisted or subscribe to my blacklist. Although I don't recommend doing that as my blacklist isn't ideal for this sort of thing. I was planning on making dedicated blacklists that can be followed for remove the worse spammers. You can however individually blacklist him and it should stop if you use PeakD.