text: from django.contrib.auth import get_user_model
  from django.db import models
  from django.utils.translation import ugettext as _
  from django_mailbox.models import Mailbox
  
  
  __all__ = ["UserMailbox"]
  
  
  class UserMailbox(models.Model):
      mailbox = models.OneToOneField(
          Mailbox, on_delete=models.CASCADE, related_name="user", primary_key=True
      )
      user = models.ForeignKey(
          get_user_model(), on_delete=models.CASCADE, related_name="mailboxes"
      )
  
      created_on = models.DateTimeField(auto_now_add=True, editable=False)
  
      class Meta:
          verbose_name = _("User Mailbox")
          verbose_name_plural = _("User Mailboxes")
          ordering = ("user",)
  
      def __str__(self):
          return self.user.__str__()
  