text: from django.db import models
  
  from direct_mail.audience.models import Audience
  from direct_mail.users.models import User
  
  
  class DeliveryType(models.Model):
      name = models.CharField(max_length=32)
      price = models.ImageField(default=0)
      description = models.TextField(blank=True)
  
      def __str__(self):
          return self.name
  
  
  class Letter(models.Model):
      file = models.FileField(null=True, blank=True)
      delivery_type = models.ForeignKey(DeliveryType, default=1)
      audience = models.ManyToManyField(Audience, default=1)
      customer = models.ForeignKey(User, default=1)
  
      date_created = models.DateTimeField(auto_now_add=True, null=True)
  
  