Daal, as a gmail user you can set up a filter that will delete any email that comes in that has the user name of the person you put on ignore.
I have a bunch of idiots on ignore and I get email updatest from the ET system that they have posted on my threads. It is a trivial change to update the ET system to this behavior to what you are suggesting, that I have asked for it repeatedly. I believe Baron is trying to do this in a future version, but it is tiresome waiting for it. If I have someone on ignore, I don't want to know they exist and certainly not polluting my inbox, since they have won that right from me. The easiest thing is to turn off email updates altogether from the ET system, and check your threads x times a day, which is what I have come to the conclusion to do so that I don't get emails. Another way would be to allow email updates only for threads that you subscribe to, not automatically be subscribed to a thread just because you post in it. This could be an option. That way you could post to your hearts content without automatically receiving emails from that thread. This would work perfectly for me. People in the past have suggested being able to self administrate your own threads. This is very dangerous power, but in the absence of the management upholding their own constitution, there is no way to stop trolls or even bots from posting on your threads.