Hidden thread but still getting email alerts

[Becca19962014]

I've hidden a thread which I was finding upsetting. It's been removed from my watched list but I'm getting emails letting me know someone has posted on that thread still and accidentally ended up opening it.

I thought hidden threads meant no more email alerts and the thread was hidden?

I'm Watching a few threads at the moment and tend to just click on the link in an email to read any updates. I don't often hide threads so didn't expect this to happen.