When I finish the form and click create account ，it displayed “reCAPTCHA is required”, but I can’t receive the letter. The email address is correct, I promise, my forum account used the same email address. Anyone can help me?
Try it in a different browser or try it in incognito mode.
It looks like you are using some kind of add-on or network filter which prevents the reCAPTCHA plugin to load. As already suggested, try to use either a different browser, deactivate your add-on or just try to register the account by using your mobile phone.