diff --git a/app/mailers/devise_user_mailer.rb b/app/mailers/devise_user_mailer.rb
index 77986e421..2fc3446ee 100644
--- a/app/mailers/devise_user_mailer.rb
+++ b/app/mailers/devise_user_mailer.rb
@@ -5,6 +5,7 @@ class DeviseUserMailer < Devise::Mailer
   include Devise::Controllers::UrlHelpers # Optional. eg. `confirmation_url`
   include MailerMonitoringConcern
   layout 'mailers/layout'
+  before_action :add_delivery_method, if: :forced_delivery?
 
   def template_paths
     ['devise_mailer']
@@ -16,4 +17,12 @@ class DeviseUserMailer < Devise::Mailer
     @prefill_token = opts[:prefill_token]
     super
   end
+
+  def add_delivery_method
+    headers[BalancerDeliveryMethod::FORCE_DELIVERY_METHOD_HEADER] = SafeMailer.forced_delivery_method
+  end
+
+  def forced_delivery?
+    SafeMailer&.forced_delivery_method.present?
+  end
 end
diff --git a/spec/mailers/devise_user_mailer_spec.rb b/spec/mailers/devise_user_mailer_spec.rb
new file mode 100644
index 000000000..f3c82701f
--- /dev/null
+++ b/spec/mailers/devise_user_mailer_spec.rb
@@ -0,0 +1,16 @@
+RSpec.describe DeviseUserMailer, type: :mailer do
+  let(:user) { create(:user) }
+  let(:token) { SecureRandom.hex }
+  describe '.confirmation_instructions' do
+    context 'without SafeMailer configured' do
+      subject { described_class.confirmation_instructions(user, token, opts = {}) }
+      it { expect(subject[BalancerDeliveryMethod::FORCE_DELIVERY_METHOD_HEADER]&.value).to eq(nil) }
+    end
+    context 'with SafeMailer configured' do
+      let(:forced_delivery_method) { :kikoo }
+      before { allow(SafeMailer).to receive(:forced_delivery_method).and_return(forced_delivery_method) }
+      subject { described_class.confirmation_instructions(user, token, opts = {}) }
+      it { expect(subject[BalancerDeliveryMethod::FORCE_DELIVERY_METHOD_HEADER]&.value).to eq(forced_delivery_method.to_s) }
+    end
+  end
+end