如何在我的Django项目中设置唯一的邮件注册？

from django.contrib.auth.models import AbstractUser
from django.db import models

class CustomUser(AbstractUser):
    email = models.EmailField(unique=True)

AUTH_USER_MODEL = 'your_app.CustomUser'

from django.contrib.auth.forms import UserCreationForm

class CustomUserCreationForm(UserCreationForm):
    class Meta:
        model = CustomUser
        fields = ('email', 'password1', 'password2')

    def clean_email(self):
        email = self.cleaned_data.get('email')
        if CustomUser.objects.filter(email=email).exists():
            raise forms.ValidationError("该邮件地址已被注册")
        return email

from django.contrib.auth import login
from django.shortcuts import render, redirect

def register(request):
    if request.method == 'POST':
        form = CustomUserCreationForm(request.POST)
        if form.is_valid():
            user = form.save()
            login(request, user)
            return redirect('home')
    else:
        form = CustomUserCreationForm()
    return render(request, 'registration/register.html', {'form': form})