diff --git a/app/lib/balancer_delivery_method.rb b/app/lib/balancer_delivery_method.rb
index 9052780ad..1fd9be5fb 100644
--- a/app/lib/balancer_delivery_method.rb
+++ b/app/lib/balancer_delivery_method.rb
@@ -14,6 +14,7 @@
 #
 # Be sure to restart your server when you modify this file.
 class BalancerDeliveryMethod
+  FORCE_DELIVERY_METHOD_HEADER = 'X-deliver-with'
   # Allows configuring the random number generator used for selecting a delivery method,
   # mostly for testing purposes.
   mattr_accessor :random, default: Random.new
@@ -39,7 +40,13 @@ class BalancerDeliveryMethod
 
   private
 
+  def force_delivery_method?(mail)
+    @delivery_methods.keys.map(&:to_s).include?(mail[FORCE_DELIVERY_METHOD_HEADER]&.value)
+  end
+
   def delivery_method(mail)
+    return mail[FORCE_DELIVERY_METHOD_HEADER].value.to_sym if force_delivery_method?(mail)
+
     @delivery_methods
       .flat_map { |delivery_method, weight| [delivery_method] * weight }
       .sample(random: self.class.random)
diff --git a/spec/lib/balancer_delivery_method_spec.rb b/spec/lib/balancer_delivery_method_spec.rb
index 3ba08bb78..bf5e39b52 100644
--- a/spec/lib/balancer_delivery_method_spec.rb
+++ b/spec/lib/balancer_delivery_method_spec.rb
@@ -5,6 +5,20 @@ RSpec.describe BalancerDeliveryMethod do
     end
   end
 
+  class ImportantEmail < ApplicationMailer
+    before_action :set_x_deliver_with
+
+    def greet(name)
+      mail(to: "smtp_to", from: "smtp_from", body: "Hello #{name}")
+    end
+
+    private
+
+    def set_x_deliver_with
+      headers['X-deliver-with'] = :mock_smtp
+    end
+  end
+
   class TestMail
     def self.deliveries
       @deliveries ||= []
@@ -46,6 +60,7 @@ RSpec.describe BalancerDeliveryMethod do
     ActionMailer::Base.add_delivery_method :balancer, BalancerDeliveryMethod
 
     ExampleMailer.delivery_method = :balancer
+    ImportantEmail.delivery_method = :balancer
   end
 
   context 'when a single delivery method is provided' do
@@ -101,6 +116,35 @@ RSpec.describe BalancerDeliveryMethod do
     end
   end
 
+  context 'SafeMailer.important_email_use_delivery_method is present' do
+    before do
+      allow(SafeMailer).to receive(:important_email_use_delivery_method).and_return(delivery_method)
+      ActionMailer::Base.balancer_settings = { mock_smtp: 10, mock_sendmail: 5 }
+
+      rng_sequence = [3, 14, 1]
+      BalancerDeliveryMethod.random = FixedSequence.new(rng_sequence)
+    end
+
+    after do
+      BalancerDeliveryMethod.random = Random.new
+    end
+
+    context 'known delivery_method & email is important' do
+      let(:delivery_method) { :mock_smtp }
+
+      it 'sends emails given the forced_delivery_method' do
+        mail1 = ImportantEmail.greet('Lucia').deliver_now
+        expect(mail1).to have_been_delivered_using(MockSmtp)
+
+        mail2 = ImportantEmail.greet('Damian').deliver_now
+        expect(mail2).to have_been_delivered_using(MockSmtp)
+
+        mail3 = ImportantEmail.greet('Rahwa').deliver_now
+        expect(mail3).to have_been_delivered_using(MockSmtp)
+      end
+    end
+  end
+
   # Helpers
 
   def have_been_delivered_using(delivery_class)