For a while I have noticed that email notifications to certain domains just don't seem to work: those emails keep bouncing back and are not delivered successfully. This seems to be the case specifically for emails to the domains: web.de and gmx (with any TLD: .de, .com, .net, .co.uk, etc).
Unfortunately there is really nothing I can do about this, except letting you know. If your notifications bounce, you will receive a message when logging in to Chaturfier, with an explanation why emails bounce. In the case of those aforementioned domains it's because of their system wide SPAM detection, which seems to be convinced that Chaturfier notifications are SPAM.
If you use one of those email services then my advice is simply to switch to a better one, like Gmail for instance. You can change your email address in the account settings. Alternatively you may try another channel for delivery of your notifications, like Telegram.
Also see my previous post on this subject.