diff --git a/notify-service/notify-api/devops/vaults.gcp.env b/notify-service/notify-api/devops/vaults.gcp.env
index 42e56f4d..df8ac057 100644
--- a/notify-service/notify-api/devops/vaults.gcp.env
+++ b/notify-service/notify-api/devops/vaults.gcp.env
@@ -11,7 +11,6 @@ NOTIFY_DATABASE_NAME="op://database/$APP_ENV/notify-db-gcp/NOTIFY_DATABASE_NAME"
 NOTIFY_DATABASE_SCHEMA="op://database/$APP_ENV/notify-db-gcp/NOTIFY_DATABASE_SCHEMA"
 MILLIONVERIFIER_API_URL="op://notify/$APP_ENV/millionverifier/MILLIONVERIFIER_API_URL"
 MILLIONVERIFIER_API_KEY="op://notify/$APP_ENV/millionverifier/MILLIONVERIFIER_API_KEY"
-GCP_AUTH_KEY="op://gcp-queue/$APP_ENV/c4hnrd/COMMON_GCP_AUTH_KEY"
 AUDIENCE="op://gcp-queue/$APP_ENV/base/AUDIENCE"
 PUBLISHER_AUDIENCE="op://gcp-queue/$APP_ENV/base/PUBLISHER_AUDIENCE"
 DELIVERY_GCNOTIFY_TOPIC="op://gcp-queue/$APP_ENV/topics/NOTIFY_DELIVERY_GCNOTIFY_TOPIC"
diff --git a/notify-service/notify-api/src/notify_api/config.py b/notify-service/notify-api/src/notify_api/config.py
index ffb1bdd2..6930c8a2 100644
--- a/notify-service/notify-api/src/notify_api/config.py
+++ b/notify-service/notify-api/src/notify_api/config.py
@@ -70,7 +70,6 @@ class Config:  # pylint: disable=too-few-public-methods
         JWT_OIDC_JWKS_CACHE_TIMEOUT = 300
 
     # PUBSUB
-    GCP_AUTH_KEY = os.getenv("GCP_AUTH_KEY", "")
     AUDIENCE = os.getenv("AUDIENCE", "https://pubsub.googleapis.com/google.pubsub.v1.Subscriber")
     PUBLISHER_AUDIENCE = os.getenv("PUBLISHER_AUDIENCE", "https://pubsub.googleapis.com/google.pubsub.v1.Publisher")
     DELIVERY_GCNOTIFY_TOPIC = os.getenv("DELIVERY_GCNOTIFY_TOPIC", "")
diff --git a/notify-service/notify-delivery/devops/vaults.gcp.env b/notify-service/notify-delivery/devops/vaults.gcp.env
index 21cc2a52..32704f20 100644
--- a/notify-service/notify-delivery/devops/vaults.gcp.env
+++ b/notify-service/notify-delivery/devops/vaults.gcp.env
@@ -7,7 +7,6 @@ NOTIFY_DATABASE_INSTANCE_CONNECTION_NAME="op://database/$APP_ENV/notify-db-gcp/N
 NOTIFY_DATABASE_USERNAME="op://database/$APP_ENV/notify-db-gcp/NOTIFY_DATABASE_USERNAME"
 NOTIFY_DATABASE_SCHEMA="op://database/$APP_ENV/notify-db-gcp/NOTIFY_DATABASE_SCHEMA"
 NOTIFY_DATABASE_NAME="op://database/$APP_ENV/notify-db-gcp/NOTIFY_DATABASE_NAME"
-GCP_AUTH_KEY="op://gcp-queue/$APP_ENV/c4hnrd/COMMON_GCP_AUTH_KEY"
 VERIFY_PUBSUB_EMAIL="op://gcp-queue/$APP_ENV/c4hnrd/COMMON_SERVICE_ACCOUNT"
 AUDIENCE="op://gcp-queue/$APP_ENV/base/AUDIENCE"
 PUBLISHER_AUDIENCE="op://gcp-queue/$APP_ENV/base/PUBLISHER_AUDIENCE"
diff --git a/notify-service/notify-delivery/devops/vaults.ocp.env b/notify-service/notify-delivery/devops/vaults.ocp.env
index 9251a44d..fc8aa709 100644
--- a/notify-service/notify-delivery/devops/vaults.ocp.env
+++ b/notify-service/notify-delivery/devops/vaults.ocp.env
@@ -7,7 +7,6 @@ NOTIFY_DATABASE_INSTANCE_CONNECTION_NAME=op://database/$APP_ENV/notify-db-gcp/NO
 NOTIFY_DATABASE_USERNAME=op://database/$APP_ENV/notify-db-gcp/NOTIFY_DATABASE_USERNAME
 NOTIFY_DATABASE_NAME=op://database/$APP_ENV/notify-db-gcp/NOTIFY_DATABASE_NAME
 NOTIFY_DATABASE_SCHEMA=op://database/$APP_ENV/notify-db-gcp/NOTIFY_DATABASE_SCHEMA
-GCP_AUTH_KEY=op://gcp-queue/$APP_ENV/c4hnrd/COMMON_GCP_AUTH_KEY
 VERIFY_PUBSUB_EMAIL=op://gcp-queue/$APP_ENV/c4hnrd/COMMON_SERVICE_ACCOUNT
 AUDIENCE=op://gcp-queue/$APP_ENV/base/AUDIENCE
 PUBLISHER_AUDIENCE=op://gcp-queue/$APP_ENV/base/PUBLISHER_AUDIENCE
diff --git a/notify-service/notify-delivery/src/notify_delivery/config.py b/notify-service/notify-delivery/src/notify_delivery/config.py
index 6fa2541e..af4a8944 100644
--- a/notify-service/notify-delivery/src/notify_delivery/config.py
+++ b/notify-service/notify-delivery/src/notify_delivery/config.py
@@ -73,7 +73,6 @@ class Config:
         GC_NOTIFY_HOUSING_EMAIL_REPLY_TO_ID = os.getenv("GC_NOTIFY_HOUSING_EMAIL_REPLY_TO_ID", "")
 
     # GCP PubSub
-    GCP_AUTH_KEY = os.getenv("GCP_AUTH_KEY", "")
     AUDIENCE = os.getenv("AUDIENCE", "https://pubsub.googleapis.com/google.pubsub.v1.Subscriber")
     PUBLISHER_AUDIENCE = os.getenv("PUBLISHER_AUDIENCE", "https://pubsub.googleapis.com/google.pubsub.v1.Publisher")
     VERIFY_PUBSUB_EMAIL = os.getenv("VERIFY_PUBSUB_EMAIL", None)
diff --git a/notify-service/notify-delivery/tests/unit/services/providers/test_email_smtp_provider.py b/notify-service/notify-delivery/tests/unit/services/providers/test_email_smtp_provider.py
index a8193c93..c061d6a5 100644
--- a/notify-service/notify-delivery/tests/unit/services/providers/test_email_smtp_provider.py
+++ b/notify-service/notify-delivery/tests/unit/services/providers/test_email_smtp_provider.py
@@ -63,13 +63,13 @@ def _create_mock_app(self, config_override=None):
         """Helper to create properly configured mock app."""
         config = {**self.mock_config, **(config_override or {})}
         mock_app = Mock()
-        mock_app.config.get.side_effect = lambda key, default=None: config.get(key, default)
+        mock_app.config.get.side_effect = config.get
         return mock_app
 
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_email_smtp_initialization(self, mock_current_app):
         """Test EmailSMTP class initialization."""
-        mock_current_app.config.get.side_effect = lambda key: self.mock_config.get(key)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         email_smtp = EmailSMTP(self.mock_notification)
 
@@ -82,7 +82,7 @@ def test_email_smtp_initialization(self, mock_current_app):
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_send_email_production_environment(self, mock_current_app, mock_smtp_class):
         """Test email sending in production environment."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -101,7 +101,7 @@ def test_send_email_production_environment(self, mock_current_app, mock_smtp_cla
     def test_send_email_development_environment(self, mock_current_app, mock_smtp_class):
         """Test email sending in development environment with subject suffix."""
         dev_config = {**self.mock_config, "DEPLOYMENT_ENV": "development"}
-        mock_current_app.config.get.side_effect = lambda key, default=None: dev_config.get(key, default)
+        mock_current_app.config.get.side_effect = dev_config.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -118,7 +118,7 @@ def test_send_email_development_environment(self, mock_current_app, mock_smtp_cl
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_send_email_multiple_recipients(self, mock_current_app, mock_smtp_class):
         """Test email sending to multiple recipients."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         multi_recipient_notification = Notification(
             id=1,
@@ -143,7 +143,7 @@ def test_send_email_multiple_recipients(self, mock_current_app, mock_smtp_class)
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_send_email_with_attachments(self, mock_current_app, mock_smtp_class):
         """Test email sending with file attachments."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         attachment = Attachment(file_name="test_document.pdf", file_bytes=b"fake pdf content")
         content_with_attachments = Content(
@@ -173,7 +173,7 @@ def test_send_email_with_attachments(self, mock_current_app, mock_smtp_class):
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_send_email_unicode_attachment_filename(self, mock_current_app, mock_smtp_class):
         """Test email sending with unicode characters in attachment filename."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         attachment = Attachment(file_name="tëst_dócümént_ñäme.pdf", file_bytes=b"fake pdf content")
         content_with_attachments = Content(
@@ -205,7 +205,7 @@ def test_send_email_unicode_attachment_filename(self, mock_current_app, mock_smt
     @patch("notify_delivery.services.providers.email_smtp.logger")
     def test_send_email_smtp_connection_error(self, mock_logger, mock_current_app, mock_smtp_class):
         """Test handling of SMTP connection errors."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         mock_smtp_class.side_effect = smtplib.SMTPException("Connection failed")
 
@@ -221,7 +221,7 @@ def test_send_email_smtp_connection_error(self, mock_logger, mock_current_app, m
     @patch("notify_delivery.services.providers.email_smtp.logger")
     def test_send_email_individual_recipient_error(self, mock_logger, mock_current_app, mock_smtp_class):
         """Test handling of individual recipient send errors."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         multi_recipient_notification = Notification(
             id=1,
@@ -253,7 +253,7 @@ def sendmail_side_effect(from_addr, to_addrs, msg):
     def test_send_email_empty_deployment_env(self, mock_current_app, mock_smtp_class):
         """Test email sending with empty deployment environment."""
         empty_env_config = {**self.mock_config, "DEPLOYMENT_ENV": ""}
-        mock_current_app.config.get.side_effect = lambda key, default=None: empty_env_config.get(key, default)
+        mock_current_app.config.get.side_effect = empty_env_config.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -270,7 +270,7 @@ def test_send_email_empty_deployment_env(self, mock_current_app, mock_smtp_class
     def test_send_email_missing_deployment_env(self, mock_current_app, mock_smtp_class):
         """Test email sending with missing deployment environment config."""
         config_without_env = {k: v for k, v in self.mock_config.items() if k != "DEPLOYMENT_ENV"}
-        mock_current_app.config.get.side_effect = lambda key, default=None: config_without_env.get(key, default)
+        mock_current_app.config.get.side_effect = config_without_env.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -285,7 +285,7 @@ def test_send_email_missing_deployment_env(self, mock_current_app, mock_smtp_cla
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_send_email_no_content_error(self, mock_current_app):
         """Test email sending with notification having no content."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         notification_no_content = Notification(
             id=1,
@@ -306,7 +306,7 @@ def test_send_email_no_content_error(self, mock_current_app):
     def test_send_email_staging_environment(self, mock_current_app, mock_smtp_class):
         """Test email sending in staging environment."""
         staging_config = {**self.mock_config, "DEPLOYMENT_ENV": "staging"}
-        mock_current_app.config.get.side_effect = lambda key, default=None: staging_config.get(key, default)
+        mock_current_app.config.get.side_effect = staging_config.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -322,7 +322,7 @@ def test_send_email_staging_environment(self, mock_current_app, mock_smtp_class)
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_send_email_message_structure(self, mock_current_app, mock_smtp_class):
         """Test that email message structure is correctly formatted."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -346,7 +346,7 @@ def test_send_email_message_structure(self, mock_current_app, mock_smtp_class):
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_send_invalid_content_structure(self, mock_current_app):
         """Test sending with invalid content structure."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         # Create content without required attributes
         invalid_content = MagicMock()
@@ -372,7 +372,7 @@ def test_send_invalid_content_structure(self, mock_current_app):
     @patch("notify_delivery.services.providers.email_smtp.current_app", new_callable=Mock)
     def test_send_with_whitespace_recipients(self, mock_current_app, mock_smtp_class):
         """Test email sending with recipients containing whitespace."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         notification_with_spaces = Notification(
             id=1,
@@ -398,7 +398,7 @@ def test_send_with_whitespace_recipients(self, mock_current_app, mock_smtp_class
     @patch("notify_delivery.services.providers.email_smtp.logger")
     def test_send_general_exception_handling(self, mock_logger, mock_current_app, mock_smtp_class):
         """Test general exception handling during SMTP connection."""
-        mock_current_app.config.get.side_effect = lambda key, default=None: self.mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = self.mock_config.get
 
         mock_smtp_class.side_effect = Exception("Unexpected error")
 
@@ -415,7 +415,7 @@ def test_send_general_exception_handling(self, mock_logger, mock_current_app, mo
     def test_prepare_subject_production(self, mock_current_app):
         """Test subject preparation in production environment."""
         production_config = {**self.mock_config, "DEPLOYMENT_ENV": "production"}
-        mock_current_app.config.get.side_effect = lambda key, default=None: production_config.get(key, default)
+        mock_current_app.config.get.side_effect = production_config.get
 
         email_smtp = EmailSMTP(self.mock_notification)
         result = email_smtp._prepare_subject("Test Subject")
@@ -426,7 +426,7 @@ def test_prepare_subject_production(self, mock_current_app):
     def test_prepare_subject_development(self, mock_current_app):
         """Test subject preparation in development environment."""
         dev_config = {**self.mock_config, "DEPLOYMENT_ENV": "development"}
-        mock_current_app.config.get.side_effect = lambda key, default=None: dev_config.get(key, default)
+        mock_current_app.config.get.side_effect = dev_config.get
 
         email_smtp = EmailSMTP(self.mock_notification)
         result = email_smtp._prepare_subject("Test Subject")
@@ -437,7 +437,7 @@ def test_prepare_subject_development(self, mock_current_app):
     def test_prepare_subject_unknown_env(self, mock_current_app):
         """Test subject preparation with unknown environment."""
         config_without_env = {k: v for k, v in self.mock_config.items() if k != "DEPLOYMENT_ENV"}
-        mock_current_app.config.get.side_effect = lambda key, default=None: config_without_env.get(key, default)
+        mock_current_app.config.get.side_effect = config_without_env.get
 
         email_smtp = EmailSMTP(self.mock_notification)
         result = email_smtp._prepare_subject("Test Subject")
@@ -448,7 +448,7 @@ def test_prepare_subject_unknown_env(self, mock_current_app):
     def test_prepare_subject_empty_env(self, mock_current_app):
         """Test subject preparation with empty deployment environment."""
         empty_env_config = {**self.mock_config, "DEPLOYMENT_ENV": ""}
-        mock_current_app.config.get.side_effect = lambda key, default=None: empty_env_config.get(key, default)
+        mock_current_app.config.get.side_effect = empty_env_config.get
 
         email_smtp = EmailSMTP(self.mock_notification)
         result = email_smtp._prepare_subject("Test Subject")
diff --git a/notify-service/notify-delivery/tests/unit/services/test_email_smtp_service.py b/notify-service/notify-delivery/tests/unit/services/test_email_smtp_service.py
index df455f89..2a92d38a 100644
--- a/notify-service/notify-delivery/tests/unit/services/test_email_smtp_service.py
+++ b/notify-service/notify-delivery/tests/unit/services/test_email_smtp_service.py
@@ -56,11 +56,11 @@ def test_email_smtp_init(self, mock_current_app):
         """Test EmailSMTP initialization."""
         # Arrange
         mock_config = MagicMock()
-        mock_config.get.side_effect = lambda key: {
+        mock_config.get.side_effect = {
             "MAIL_SERVER": "smtp.example.com",
             "MAIL_PORT": self.TEST_SMTP_PORT,
             "MAIL_FROM_ID": "sender@example.com",
-        }.get(key)
+        }.get
         mock_current_app.config = mock_config
 
         # Act
@@ -83,7 +83,7 @@ def test_send_email_success_single_recipient(self, mock_current_app, mock_smtp_c
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "production",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -114,7 +114,7 @@ def test_send_email_success_multiple_recipients(self, mock_current_app, mock_smt
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "production",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         # Create notification with multiple recipients
         multi_recipient_notification = Notification(
@@ -156,7 +156,7 @@ def test_send_email_with_development_environment(self, mock_current_app, mock_sm
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "development",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -183,7 +183,7 @@ def test_send_email_with_attachments(self, mock_current_app, mock_smtp_class):
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "production",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         # Create content with attachments
         attachment = Attachment(file_name="test_document.pdf", file_bytes=b"fake pdf content")
@@ -226,7 +226,7 @@ def test_send_email_attachment_unicode_filename(self, mock_current_app, mock_smt
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "production",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         # Create content with unicode filename attachment
         attachment = Attachment(file_name="tëst_dócümént_ñäme.pdf", file_bytes=b"fake pdf content")
@@ -270,7 +270,7 @@ def test_send_email_smtp_connection_error(self, mock_logger, mock_current_app, m
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "production",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         mock_smtp_class.side_effect = smtplib.SMTPException("Connection failed")
 
@@ -296,7 +296,7 @@ def test_send_email_individual_send_error(self, mock_logger, mock_current_app, m
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "production",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         # Create notification with multiple recipients
         multi_recipient_notification = Notification(
@@ -338,7 +338,7 @@ def test_send_email_empty_deployment_env(self, mock_current_app):
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         email_smtp = EmailSMTP(self.mock_notification)
 
@@ -365,7 +365,7 @@ def test_send_email_missing_deployment_env(self, mock_current_app):
             "MAIL_FROM_ID": "sender@example.com",
             # DEPLOYMENT_ENV is missing
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         email_smtp = EmailSMTP(self.mock_notification)
 
@@ -392,7 +392,7 @@ def test_send_email_production_environment_no_suffix(self, mock_current_app, moc
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "production",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         mock_server = Mock()
         mock_smtp_class.return_value.__enter__.return_value = mock_server
@@ -418,7 +418,7 @@ def test_email_smtp_with_none_content(self, mock_current_app):
             "MAIL_FROM_ID": "sender@example.com",
             "DEPLOYMENT_ENV": "production",
         }
-        mock_current_app.config.get.side_effect = lambda key, default=None: mock_config.get(key, default)
+        mock_current_app.config.get.side_effect = mock_config.get
 
         notification_no_content = Notification(
             id=1,