Another thing to check is any blocked email addreses you have. When I used my Yahoo email, I noticed I wasn't getting replies even when I went back in and verified that I was subscribed (a search will reveal a thread along these same lines that I did back then). After checking, I realised that I had blocked all emails from the domain "gmail.com". The emails from the forum come from that domain so it was blocking all of them and not allowing them through. Simply deleting that block got me emails again.