Add signal to send registration email upon user creation

backend/cli.py

@@ -1,4 +1,4 @@
-import argparse
+ccimport argparse
 import multiprocessing
 import os
 import platform

backend/users/apps.py

@@ -4,3 +4,6 @@ from django.apps import AppConfig
 class UsersConfig(AppConfig):
     default_auto_field = "django.db.models.BigAutoField"
     name = "users"
+
+    def ready(self):
+        import users.signals

backend/users/signals.py

@@ -0,0 +1,32 @@
+from django.db.models.signals import post_save
+from django.dispatch import receiver
+from django.contrib.auth import get_user_model
+from django.core.mail import send_mail, BadHeaderError
+from django.conf import settings
+import logging
+
+logger = logging.getLogger(__name__)
+User = get_user_model()
+
+@receiver(post_save, sender=User)
+def send_registration_email(sender, instance, created, **kwargs):
+    if created:
+        subject = 'Welcome to Our Service!'
+        message = (
+            f"Hello {instance.username},\n\n"
+            "Thank you for registering with us. Your account has been successfully created.\n\n"
+            "You can now log in and start using our service.\n\n"
+            "Best regards,\nThe Team"
+        )
+        try:
+            send_mail(
+                subject,
+                message,
+                settings.DEFAULT_FROM_EMAIL,
+                [instance.email],
+                fail_silently=False,
+            )
+        except BadHeaderError:
+            logger.error("Invalid header found while sending email to: %s", instance.email)
+        except Exception as e:
+            logger.error("Error sending registration email to %s: %s", instance.email, e)