Not sure how I feel with this. On one side, not many people have Vivaldi email accounts, so probably not a big deal at this point. And if you're going to have a code of conduct, at least it's a CoC with teeth.

On the other side, if someone doesn't like what you say on the forum for whatever reason (example reason given: Telling jokes or being sarcastic) and enough people report your posts, you may find yourself losing all access to your emails. That seems potentially disproportionate.