diff --git a/payments/gateways/__init__.py b/payments/gateways/__init__.py
index 2c38824e..9159967f 100644
--- a/payments/gateways/__init__.py
+++ b/payments/gateways/__init__.py
@@ -1,2 +1,12 @@
 class UnknownGatewayError(Exception):
     pass
+
+
+class AbstractGateway:
+    @staticmethod
+    def process_transaction(transaction):
+        raise NotImplementedError
+
+    @staticmethod
+    def process_callback(transaction):
+        raise NotImplementedError
diff --git a/payments/signals.py b/payments/signals.py
index 79fbd86a..62e6549c 100644
--- a/payments/signals.py
+++ b/payments/signals.py
@@ -21,7 +21,8 @@ def process_transaction_changes(instance, created, **_kwargs):
         except Exception as e:  # noqa:
             instance.process = {"status": "NOGATEWAY", "error": str(e)}
     if not created:
-        if "success" in str(instance.process).lower() and "notify" in str(instance.process).lower():
+        status = instance.process.get("status", "").lower()
+        success = instance.process.get("success", False)
+
+        if "success" in status or success:
             balance_deposit_email.delay(instance.uuid)
-        if "fail" in str(instance.process).lower() and "notify" in str(instance.process).lower():
-            pass