Let's start by taking a look at your spam folder. If the letter isn't there, perhaps try using a different browser and clearing your cache.
If you're using an Android device, this may be the cause of the issue. We are working on it, but for now please try a different device.
If the problem still happens, do let us know by sending a text to our blue messenger in the lower right corner of the page or to support@chessarena.com and we'll work on it from our end!