If you’re a RoadRunner (rr.com) user you won’t be getting email updates from watched topics, PM, etc, at the moment. RoadRunner have a policy of blocking whole sub-nets that they’ve had spam from. My server has 4 IP addresses in the 81.29.70 sub-net and around 2 months ago another server (not one of mine) in the same sub-net had a spam problem. The server owner wasn’t the originator of the spam, the spammers found a loophole in it’s email security settings and used it as a spam backdoor. I reported the problem at the time and the problem was resolved (or at least what I saw of it went away.
Unfortunately RoadRunner will only deal with the owner of the sub-net, so I’ve had to involve the server hosting company. They’re on with the job, but are finding it slow to get responses from RoadRunner.