Monkeypatch mailového backendu

various/mail_prefixer.py

@@ -0,0 +1,16 @@
+"""A simple email backend, which only prepends all subjects with a string.
+
+Used to distinguish testing emails from production ones."""
+
+# We try to monkeypatch django.core.mail.backends.smtp :-)
+
+from djago.core.mail.backends.smtp import EmailBackend as DjangoSMTPBackend
+
+class PrefixingMailBackend(DjangoSMTPBackend):
+	# method _send is not probably meant to be monkey_patched, so we patch send_messages instead.
+	def send_messages(self, messages):
+		prefix = '[Mail z testwebu]'
+		for message in messages:
+			# We hope that this is a django.core.mail.message.EmailMessage
+			message.subject = prefix + ' ' + message.subject
+		return super().send_messages(messages)