diff --git a/spec/mailers/administrator_notifications/shared/smtp_config_shared.rb b/spec/mailers/administrator_notifications/shared/smtp_config_shared.rb
index 96d4dbb0d..0bb18a337 100644
--- a/spec/mailers/administrator_notifications/shared/smtp_config_shared.rb
+++ b/spec/mailers/administrator_notifications/shared/smtp_config_shared.rb
@@ -1,11 +1,9 @@
 # frozen_string_literal: true
 
 RSpec.shared_context 'with smtp config' do
-  before do
-    # We need to use allow_any_instance_of here because smtp_config_set_or_development?
-    # is defined in ApplicationMailer and needs to be stubbed for all mailer instances
-    # rubocop:disable RSpec/AnyInstance
-    allow_any_instance_of(ApplicationMailer).to receive(:smtp_config_set_or_development?).and_return(true)
-    # rubocop:enable RSpec/AnyInstance
+  around do |example|
+    # Set SMTP_ADDRESS so mailers build a Mail::Message in test without touching real SMTP.
+    # Scoped to this shared context to avoid affecting other specs.
+    with_modified_env('SMTP_ADDRESS' => 'smtp.example.com') { example.run }
   end
 end