Adding validator for email in the standard User table

Using Django Using the ORM
1

Is this addition of a validator acceptable?

from django.core.validators import EmailValidator

class User(AbstractUser):
    country = models.CharField(max_length=120, validators=validators['user']['country'])
    city = models.CharField(max_length=120) 
    street_name = models.CharField(max_length=120)
    postcode = models.CharField(max_length=20)  
    additional_address_details = models.TextField(blank=True, null=True)  
    phone_number = models.CharField(max_length=20)

    def save(self, force_insert=False, force_update=False, using=None, update_fields=None):
        
        if update_fields is not None:
            self.full_clean(exclude=update_fields)
        else:
            self.full_clean()
          
        super().save(force_insert=force_insert, force_update=force_update, 
                         using=using, update_fields=update_fields,)

User.email.validators = EmailValidator

UPD: I also wonder if django controls such restrictions as max_length=20 or leaves it to the database? If the second option, then as soon as the database returns an error, what python exception will be called? I didn’t find any information about this in the documentation (maybe I didn’t look hard enough).