Use Sendico SMTP mailbox for local notifications (#57)

backend/notifications/service/worker.go

@@ -68,6 +68,9 @@ func (s *Service) Dispatch(ctx context.Context, id string) (bool, error) {
 	if outcome.HTTPStatus != 0 {
 		fields = append(fields, zap.Int("provider_status", outcome.HTTPStatus))
 	}
+	if outcome.SMTPStatus != 0 {
+		fields = append(fields, zap.Int("provider_smtp_status", outcome.SMTPStatus))
+	}
 	if outcome.ProviderError != "" {
 		fields = append(fields, zap.String("provider_error", outcome.ProviderError))
 	}